diff --git a/configure b/configure
index 96da9b33..0ade21b9 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.67 for PSBLAS 3.0.
+# Generated by GNU Autoconf 2.66 for PSBLAS 3.0.
 #
 # Report bugs to <salvatore.filippone@uniroma2.it>.
 #
@@ -822,9 +822,8 @@ do
   fi
 
   case $ac_option in
-  *=?*) ac_optarg=`expr "X$ac_option" : '[^=]*=\(.*\)'` ;;
-  *=)   ac_optarg= ;;
-  *)    ac_optarg=yes ;;
+  *=*)	ac_optarg=`expr "X$ac_option" : '[^=]*=\(.*\)'` ;;
+  *)	ac_optarg=yes ;;
   esac
 
   # Accept the important Cygnus configure options, so we can diagnose typos.
@@ -1498,7 +1497,7 @@ test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
 PSBLAS configure 3.0
-generated by GNU Autoconf 2.67
+generated by GNU Autoconf 2.66
 
 Copyright (C) 2010 Free Software Foundation, Inc.
 This configure script is free software; the Free Software Foundation
@@ -2071,7 +2070,7 @@ $as_echo "$ac_try_echo"; } >&5
     mv -f conftest.er1 conftest.err
   fi
   $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
-  test $ac_status = 0; } > conftest.i && {
+  test $ac_status = 0; } >/dev/null && {
 	 test -z "$ac_c_preproc_warn_flag$ac_c_werror_flag" ||
 	 test ! -s conftest.err
        }; then :
@@ -2122,7 +2121,7 @@ This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
 It was created by PSBLAS $as_me 3.0, which was
-generated by GNU Autoconf 2.67.  Invocation command line was
+generated by GNU Autoconf 2.66.  Invocation command line was
 
   $ $0 $@
 
@@ -2380,7 +2379,7 @@ $as_echo "$as_me: loading site script $ac_site_file" >&6;}
       || { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "failed to load site script $ac_site_file
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
   fi
 done
 
@@ -2872,7 +2871,7 @@ sed 's/^/| /' conftest.$ac_ext >&5
 { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error 77 "Fortran compiler cannot create executables
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
@@ -2915,7 +2914,7 @@ else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "cannot compute suffix of executables: cannot compile and link
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 rm -f conftest conftest$ac_cv_exeext
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_exeext" >&5
@@ -2968,7 +2967,7 @@ $as_echo "$ac_try_echo"; } >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "cannot run Fortran compiled programs.
 If you meant to cross compile, use \`--host'.
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
     fi
   fi
 fi
@@ -3014,7 +3013,7 @@ sed 's/^/| /' conftest.$ac_ext >&5
 { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "cannot compute suffix of object files: cannot compile
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 rm -f conftest.$ac_cv_objext conftest.$ac_ext
 fi
@@ -3417,7 +3416,7 @@ fi
 test -z "$CC" && { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "no acceptable C compiler found in \$PATH
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 
 # Provide some information about the compiler.
 $as_echo "$as_me:${as_lineno-$LINENO}: checking for C compiler version" >&5
@@ -4803,11 +4802,11 @@ am_lf='
 '
 case `pwd` in
   *[\\\"\#\$\&\'\`$am_lf]*)
-    as_fn_error $? "unsafe absolute working directory name" "$LINENO" 5 ;;
+    as_fn_error $? "unsafe absolute working directory name" "$LINENO" 5;;
 esac
 case $srcdir in
   *[\\\"\#\$\&\'\`$am_lf\ \	]*)
-    as_fn_error $? "unsafe srcdir value: \`$srcdir'" "$LINENO" 5 ;;
+    as_fn_error $? "unsafe srcdir value: \`$srcdir'" "$LINENO" 5;;
 esac
 
 # Do `set' in a subshell so we don't clobber the current shell's
@@ -5529,7 +5528,7 @@ else
   # Broken: fails on valid input.
 continue
 fi
-rm -f conftest.err conftest.i conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 
   # OK, works on sane cases.  Now check whether nonexistent headers
   # can be detected and how.
@@ -5545,11 +5544,11 @@ else
 ac_preproc_ok=:
 break
 fi
-rm -f conftest.err conftest.i conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 
 done
 # Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 if $ac_preproc_ok; then :
   break
 fi
@@ -5588,7 +5587,7 @@ else
   # Broken: fails on valid input.
 continue
 fi
-rm -f conftest.err conftest.i conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 
   # OK, works on sane cases.  Now check whether nonexistent headers
   # can be detected and how.
@@ -5604,18 +5603,18 @@ else
 ac_preproc_ok=:
 break
 fi
-rm -f conftest.err conftest.i conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 
 done
 # Because of `break', _AC_PREPROC_IFELSE's cleaning code was skipped.
-rm -f conftest.i conftest.err conftest.$ac_ext
+rm -f conftest.err conftest.$ac_ext
 if $ac_preproc_ok; then :
 
 else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "C preprocessor \"$CPP\" fails sanity check
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 
 ac_ext=c
@@ -5900,7 +5899,7 @@ else
      { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error 77 "cannot compute sizeof (void *)
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
    else
      ac_cv_sizeof_void_p=0
    fi
@@ -6063,7 +6062,7 @@ else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "cannot compile a simple Fortran program
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
@@ -7257,7 +7256,7 @@ fi
 	  ;;
 	  # Ignore these flags.
 	-lang* | -lcrt*.o | -lc | -lgcc* | -lSystem | -libmil | -little \
-	  |-LANG:=* | -LIST:* | -LNO:* | -link)
+	  |-LANG:=* | -LIST:* | -LNO:*)
 	  ;;
 	-lkernel32)
 	  test x"$CYGWIN" != xyes && ac_cv_f77_libs="$ac_cv_f77_libs $ac_arg"
@@ -7452,7 +7451,7 @@ else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "linking to Fortran libraries from C fails
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 
 ac_ext=c
@@ -7614,7 +7613,7 @@ else
   { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
 $as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
 as_fn_error $? "cannot compile a simple Fortran program
-See \`config.log' for more details" "$LINENO" 5 ; }
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
@@ -8765,14 +8764,14 @@ fi
 
 # Check whether --with-rsb was given.
 if test "${with_rsb+set}" = set; then :
-  withval=$with_rsb; if test x$withval = xno; then
-want_rsb_libs= ; else if test x$withval = xyes ; then want_rsb_libs=yes ; else want_rsb_libs="$withval" ; fi ; fi
+  withval=$with_rsb; if test x"$withval" = xno; then
+want_rsb_libs= ; else if test x"$withval" = xyes ; then want_rsb_libs=yes ; else want_rsb_libs="$withval" ; fi ; fi
 else
   want_rsb_libs=""
 fi
 
-if test x$want_rsb_libs != x ; then
-	if test x$want_rsb_libs = xyes ; then
+if test x"$want_rsb_libs" != x ; then
+	if test x"$want_rsb_libs" = xyes ; then
 		want_rsb_libs="`librsb-config --static --ldflags`"
 	else
 		if test -d "$want_rsb_libs" ; then
@@ -8790,7 +8789,7 @@ LIBS="$RSB_LIBS ${LIBS}"
 
 # Check whether --with-metis was given.
 if test "${with_metis+set}" = set; then :
-  withval=$with_metis; psblas_cv_metis=$withval
+  withval=$with_metis; psblas_cv_metis="$withval"
 else
   psblas_cv_metis=''
 fi
@@ -9564,7 +9563,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # values after options handling.
 ac_log="
 This file was extended by PSBLAS $as_me 3.0, which was
-generated by GNU Autoconf 2.67.  Invocation command line was
+generated by GNU Autoconf 2.66.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
   CONFIG_HEADERS  = $CONFIG_HEADERS
@@ -9621,7 +9620,7 @@ cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
 PSBLAS config.status 3.0
-configured by $0, generated by GNU Autoconf 2.67,
+configured by $0, generated by GNU Autoconf 2.66,
   with options \\"\$ac_cs_config\\"
 
 Copyright (C) 2010 Free Software Foundation, Inc.
@@ -9642,16 +9641,11 @@ ac_need_defaults=:
 while test $# != 0
 do
   case $1 in
-  --*=?*)
+  --*=*)
     ac_option=`expr "X$1" : 'X\([^=]*\)='`
     ac_optarg=`expr "X$1" : 'X[^=]*=\(.*\)'`
     ac_shift=:
     ;;
-  --*=)
-    ac_option=`expr "X$1" : 'X\([^=]*\)='`
-    ac_optarg=
-    ac_shift=:
-    ;;
   *)
     ac_option=$1
     ac_optarg=$2
@@ -9673,7 +9667,6 @@ do
     $ac_shift
     case $ac_optarg in
     *\'*) ac_optarg=`$as_echo "$ac_optarg" | sed "s/'/'\\\\\\\\''/g"` ;;
-    '') as_fn_error $? "missing file argument" ;;
     esac
     as_fn_append CONFIG_FILES " '$ac_optarg'"
     ac_need_defaults=false;;
@@ -9741,7 +9734,7 @@ do
     "depfiles") CONFIG_COMMANDS="$CONFIG_COMMANDS depfiles" ;;
     "Make.inc") CONFIG_FILES="$CONFIG_FILES Make.inc" ;;
 
-  *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5 ;;
+  *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
   esac
 done
 
@@ -9948,7 +9941,7 @@ do
   esac
   case $ac_mode$ac_tag in
   :[FHL]*:*);;
-  :L* | :C*:*) as_fn_error $? "invalid tag \`$ac_tag'" "$LINENO" 5 ;;
+  :L* | :C*:*) as_fn_error $? "invalid tag \`$ac_tag'" "$LINENO" 5;;
   :[FH]-) ac_tag=-:-;;
   :[FH]*) ac_tag=$ac_tag:$ac_tag.in;;
   esac
@@ -9976,7 +9969,7 @@ do
 	   [\\/$]*) false;;
 	   *) test -f "$srcdir/$ac_f" && ac_f="$srcdir/$ac_f";;
 	   esac ||
-	   as_fn_error 1 "cannot find input file: \`$ac_f'" "$LINENO" 5 ;;
+	   as_fn_error 1 "cannot find input file: \`$ac_f'" "$LINENO" 5;;
       esac
       case $ac_f in *\'*) ac_f=`$as_echo "$ac_f" | sed "s/'/'\\\\\\\\''/g"`;; esac
       as_fn_append ac_file_inputs " '$ac_f'"
@@ -10003,7 +9996,7 @@ $as_echo "$as_me: creating $ac_file" >&6;}
 
     case $ac_tag in
     *:-:* | *:-) cat >"$tmp/stdin" \
-      || as_fn_error $? "could not create $ac_file" "$LINENO" 5  ;;
+      || as_fn_error $? "could not create $ac_file" "$LINENO" 5 ;;
     esac
     ;;
   esac
diff --git a/configure.ac b/configure.ac
index 496c544c..86718bc4 100755
--- a/configure.ac
+++ b/configure.ac
@@ -641,10 +641,10 @@ PAC_MAKE_IS_GNUMAKE
 # Note : also umfdi_local_search, ...
 #AC_CHECK_LIB(umf,umfpack_di_solve,psblas_cv_have_umfpack=yes,psblas_cv_have_umfpack=no,[amd])
 
-AC_ARG_WITH(rsb, AC_HELP_STRING([--with-rsb], [Specify Recursive Sparse BLAS library linkage info (that is, the output of librsb-config  --static --ldflags, or a directory where the usual bin/include/lib subdirs with a regular RSB installation resides, or nothing to make the configure script invoke librsb-config)]), [if test x$withval = xno; then
-want_rsb_libs= ; else if test x$withval = xyes ; then want_rsb_libs=yes ; else want_rsb_libs="$withval" ; fi ; fi], [want_rsb_libs=""])
-if test x$want_rsb_libs != x ; then
-	if test x$want_rsb_libs = xyes ; then
+AC_ARG_WITH(rsb, AC_HELP_STRING([--with-rsb], [Specify Recursive Sparse BLAS library linkage info (that is, the output of librsb-config  --static --ldflags, or a directory where the usual bin/include/lib subdirs with a regular RSB installation resides, or nothing to make the configure script invoke librsb-config)]), [if test x"$withval" = xno; then
+want_rsb_libs= ; else if test x"$withval" = xyes ; then want_rsb_libs=yes ; else want_rsb_libs="$withval" ; fi ; fi], [want_rsb_libs=""])
+if test x"$want_rsb_libs" != x ; then
+	if test x"$want_rsb_libs" = xyes ; then
 		want_rsb_libs="`librsb-config --static --ldflags`"
 	else
 		if test -d "$want_rsb_libs" ; then
@@ -661,7 +661,7 @@ LIBS="$RSB_LIBS ${LIBS}"
 dnl AC_CHECK_HEADERS([rsb.h], [ LIBS="${LIBS} $want_rsb_libs"], [])
 
 AC_ARG_WITH(metis, AC_HELP_STRING([--with-metis=LIB], [Specify -lMETISLIBNAME or the absolute library filename.]),
-        [psblas_cv_metis=$withval],
+        [psblas_cv_metis="$withval"],
         [psblas_cv_metis=''])