diff --git a/config/pac.m4 b/config/pac.m4
index c9f55d94..bf2edf2f 100644
--- a/config/pac.m4
+++ b/config/pac.m4
@@ -1865,7 +1865,7 @@ if test "x$pac_metis_header_ok" == "xyes" ; then
    AC_LANG_POP()
 fi
 
-if test "x$pac_metis_header_ok" == "xyes" ; then 
+if test "x$pac_metis_header_ok" = "xyes" ; then 
       psblas_cv_metis_includes="$METIS_INCLUDES"
       METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
       LIBS="$METIS_LIBS -lm $LIBS";
@@ -1874,7 +1874,7 @@ if test "x$pac_metis_header_ok" == "xyes" ; then
        [psblas_cv_have_metis=yes;pac_metis_lib_ok=yes; ],
        [psblas_cv_have_metis=no;pac_metis_lib_ok=no; METIS_LIBS=""])
       AC_MSG_RESULT($pac_metis_lib_ok)
-     if test "x$pac_metis_lib_ok" == "xno" ; then 
+     if test "x$pac_metis_lib_ok" = "xno" ; then 
         dnl Maybe Lib or lib? 
         METIS_LIBDIR="-L$psblas_cv_metisdir/Lib -L$psblas_cv_metisdir/lib"
         METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
@@ -1886,24 +1886,29 @@ if test "x$pac_metis_header_ok" == "xyes" ; then
        [psblas_cv_have_metis=no;pac_metis_lib_ok=no; METIS_LIBS=""])
       AC_MSG_RESULT($pac_metis_lib_ok)
      fi
-     if test "x$pac_metis_lib_ok" == "xno" ; then 
+
+     if test "x$pac_metis_lib_ok" = "xno" ; then 
         dnl Maybe METIS/Lib? 
         METIS_LIBDIR="-L$psblas_cv_metisdir/METIS/Lib -L$psblas_cv_metisdir/METIS/Lib"
         METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
         LIBS="$METIS_LIBS -lm $SAVE_LIBS"
       AC_MSG_CHECKING([for METIS_PartGraphKway in $METIS_LIBS])
       AC_TRY_LINK_FUNC(METIS_PartGraphKway, 
-       [psblas_cv_have_metis=yes;pac_metis_lib_ok=yes; ],
-       [psblas_cv_have_metis=no;pac_metis_lib_ok=no; METIS_LIBS=""])
+       [psblas_cv_have_metis=yes;pac_metis_lib_ok="yes"; ],
+       [psblas_cv_have_metis=no;pac_metis_lib_ok="no"; METIS_LIBS=""])
       AC_MSG_RESULT($pac_metis_lib_ok)
-     fi
-fi
-if test "x$pac_metis_lib_ok" == "xyes" ; then 
+      fi
+ fi
+ AC_MSG_NOTICE([ metis lib ok $pac_metis_lib_ok])
+
+ if test "x$pac_metis_lib_ok" = "xyes" ; then 
       AC_MSG_CHECKING([for METIS_SetDefaultOptions in $LIBS])
       AC_TRY_LINK_FUNC(METIS_SetDefaultOptions, 
-       [psblas_cv_have_metis=yes;pac_metis_lib_ok=yes; ],
-       [psblas_cv_have_metis=no;pac_metis_lib_ok="no. Unusable METIS version, sorry."; METIS_LIBS=""])
+        [psblas_cv_have_metis=yes;pac_metis_lib_ok=yes; ],
+        [psblas_cv_have_metis=no;pac_metis_lib_ok="no. Unusable METIS version, sorry."; METIS_LIBS=""
+      ])
       AC_MSG_RESULT($pac_metis_lib_ok)
+
 fi
 
 LIBS="$SAVE_LIBS";
diff --git a/configure b/configure
index ccefc2c0..c03866ed 100755
--- a/configure
+++ b/configure
@@ -6873,10 +6873,10 @@ fi
 
 # Defaults for IPK/LPK
 if test x"$pac_cv_ipk_size" == x"" ; then
-  pac_cv_ipk_size=4;
+  pac_cv_ipk_size=4
 fi
 if test x"$pac_cv_lpk_size" == x"" ; then
-  pac_cv_lpk_size=8;
+  pac_cv_lpk_size=8
 fi
 # Enforce sensible combination
 if (( $pac_cv_lpk_size < $pac_cv_ipk_size )); then
@@ -9017,7 +9017,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 fi
 
-if test "x$pac_metis_header_ok" == "xyes" ; then
+if test "x$pac_metis_header_ok" = "xyes" ; then
       psblas_cv_metis_includes="$METIS_INCLUDES"
       METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
       LIBS="$METIS_LIBS -lm $LIBS";
@@ -9050,7 +9050,7 @@ rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pac_metis_lib_ok" >&5
 $as_echo "$pac_metis_lib_ok" >&6; }
-     if test "x$pac_metis_lib_ok" == "xno" ; then
+     if test "x$pac_metis_lib_ok" = "xno" ; then
                 METIS_LIBDIR="-L$psblas_cv_metisdir/Lib -L$psblas_cv_metisdir/lib"
         METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
         LIBS="$METIS_LIBS -lm $SAVE_LIBS"
@@ -9085,7 +9085,8 @@ rm -f core conftest.err conftest.$ac_objext \
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pac_metis_lib_ok" >&5
 $as_echo "$pac_metis_lib_ok" >&6; }
      fi
-     if test "x$pac_metis_lib_ok" == "xno" ; then
+
+     if test "x$pac_metis_lib_ok" = "xno" ; then
                 METIS_LIBDIR="-L$psblas_cv_metisdir/METIS/Lib -L$psblas_cv_metisdir/METIS/Lib"
         METIS_LIBS="$psblas_cv_metis $METIS_LIBDIR"
         LIBS="$METIS_LIBS -lm $SAVE_LIBS"
@@ -9110,17 +9111,20 @@ return METIS_PartGraphKway ();
 }
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
-  psblas_cv_have_metis=yes;pac_metis_lib_ok=yes;
+  psblas_cv_have_metis=yes;pac_metis_lib_ok="yes";
 else
-  psblas_cv_have_metis=no;pac_metis_lib_ok=no; METIS_LIBS=""
+  psblas_cv_have_metis=no;pac_metis_lib_ok="no"; METIS_LIBS=""
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pac_metis_lib_ok" >&5
 $as_echo "$pac_metis_lib_ok" >&6; }
-     fi
-fi
-if test "x$pac_metis_lib_ok" == "xyes" ; then
+      fi
+ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}:  metis lib ok $pac_metis_lib_ok" >&5
+$as_echo "$as_me:  metis lib ok $pac_metis_lib_ok" >&6;}
+
+ if test "x$pac_metis_lib_ok" = "xyes" ; then
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for METIS_SetDefaultOptions in $LIBS" >&5
 $as_echo_n "checking for METIS_SetDefaultOptions in $LIBS... " >&6; }
       cat confdefs.h - <<_ACEOF >conftest.$ac_ext
@@ -9145,19 +9149,40 @@ if ac_fn_c_try_link "$LINENO"; then :
   psblas_cv_have_metis=yes;pac_metis_lib_ok=yes;
 else
   psblas_cv_have_metis=no;pac_metis_lib_ok="no. Unusable METIS version, sorry."; METIS_LIBS=""
+
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pac_metis_lib_ok" >&5
 $as_echo "$pac_metis_lib_ok" >&6; }
+
 fi
 
 LIBS="$SAVE_LIBS";
 CPPFLAGS="$SAVE_CPPFLAGS";
 
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking Compatibility between metis and LPK" >&5
+$as_echo_n "checking Compatibility between metis and LPK... " >&6; }
+if  test  "x$pac_cv_lpk_size" == "x4" ; then
+  if test  "x$pac_cv_metis_idx" == "x64" ; then
+         psblas_cv_have_metis="no";
+    fi
+ fi
+ if test "x$pac_cv_lpk_size" == "x8" ; then
+   if test "x$pac_cv_metis_idx" == "x32" ; then
+         psblas_cv_have_metis="no";
+   fi
+ fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $psblas_cv_have_metis" >&5
+$as_echo "$psblas_cv_have_metis" >&6; }
+
 if test "x$pac_cv_metis_idx" == "xunknown" ; then
-   true ; # do nothing
-elif test "x$psblas_cv_have_metis" == "xyes" ; then
+       { $as_echo "$as_me:${as_lineno-$LINENO}: Unknown  METIS bitsize." >&5
+$as_echo "$as_me: Unknown  METIS bitsize." >&6;}
+     $psblas_cv_have_metis = "no";
+fi
+if test "x$psblas_cv_have_metis" == "xyes" ; then
    FDEFINES="$psblas_cv_define_prepend-DHAVE_METIS $psblas_cv_define_prepend-DMETIS_$pac_cv_metis_idx $FDEFINES"
    CDEFINES="-DHAVE_METIS_ $psblas_cv_metis_includes $CDEFINES -DMETIS_$pac_cv_metis_idx"
    METISINCFILE=$psblas_cv_metisincfile
@@ -10782,7 +10807,8 @@ fi
 
 	BLAS                  : ${BLAS_LIBS}
 
-	METIS detected        : ${psblas_cv_have_metis}
+	METIS usable          : ${psblas_cv_have_metis}
+	METIS bitsize         : ${pac_cv_metis_idx}
 	AMD detected          : ${psblas_cv_have_amd}
         LIBS                  : ${LIBS}
 	LDLIBS                : ${LDLIBS}
@@ -10810,7 +10836,8 @@ $as_echo "$as_me:
 
 	BLAS                  : ${BLAS_LIBS}
 
-	METIS detected        : ${psblas_cv_have_metis}
+	METIS usable          : ${psblas_cv_have_metis}
+	METIS bitsize         : ${pac_cv_metis_idx}
 	AMD detected          : ${psblas_cv_have_amd}
         LIBS                  : ${LIBS}
 	LDLIBS                : ${LDLIBS}
diff --git a/configure.ac b/configure.ac
index 9edcb290..8bfd5806 100755
--- a/configure.ac
+++ b/configure.ac
@@ -483,10 +483,10 @@ PAC_ARG_WITH_IPK
 PAC_ARG_WITH_LPK
 # Defaults for IPK/LPK
 if test x"$pac_cv_ipk_size" == x"" ; then
-  pac_cv_ipk_size=4;
+  pac_cv_ipk_size=4
 fi
 if test x"$pac_cv_lpk_size" == x"" ; then
-  pac_cv_lpk_size=8;
+  pac_cv_lpk_size=8
 fi
 # Enforce sensible combination
 if (( $pac_cv_lpk_size < $pac_cv_ipk_size )); then
@@ -694,9 +694,29 @@ LIBS="$RSB_LIBS ${LIBS}"
 dnl AC_CHECK_HEADERS([rsb.h], [ LIBS="${LIBS} $want_rsb_libs"], [])
 
 PAC_CHECK_METIS
+
+AC_MSG_CHECKING([Compatibility between metis and LPK])
+if  test  "x$pac_cv_lpk_size" == "x4" ; then
+  if test  "x$pac_cv_metis_idx" == "x64" ; then
+  dnl mismatch between metis size and PSBLAS LPK
+       psblas_cv_have_metis="no";
+ dnl 
+   fi
+ fi			   
+ if test "x$pac_cv_lpk_size" == "x8" ; then
+   if test "x$pac_cv_metis_idx" == "x32" ; then 
+   dnl mismatch between metis size and PSBLAS LPK
+      psblas_cv_have_metis="no";
+   fi
+ fi			   
+AC_MSG_RESULT([$psblas_cv_have_metis])
+
 if test "x$pac_cv_metis_idx" == "xunknown" ; then
-   true ; # do nothing
-elif test "x$psblas_cv_have_metis" == "xyes" ; then 
+  dnl mismatch between metis size and PSBLAS LPK
+     AC_MSG_NOTICE([Unknown  METIS bitsize.])	
+     $psblas_cv_have_metis = "no";
+fi		   
+if test "x$psblas_cv_have_metis" == "xyes" ; then 
    FDEFINES="$psblas_cv_define_prepend-DHAVE_METIS $psblas_cv_define_prepend-DMETIS_$pac_cv_metis_idx $FDEFINES"
    CDEFINES="-DHAVE_METIS_ $psblas_cv_metis_includes $CDEFINES -DMETIS_$pac_cv_metis_idx"
    METISINCFILE=$psblas_cv_metisincfile
@@ -814,7 +834,8 @@ AC_MSG_NOTICE([
 
 	BLAS                  : ${BLAS_LIBS}
 
-	METIS detected        : ${psblas_cv_have_metis}
+	METIS usable          : ${psblas_cv_have_metis}
+	METIS bitsize         : ${pac_cv_metis_idx}
 	AMD detected          : ${psblas_cv_have_amd}
         LIBS                  : ${LIBS}
 dnl Note : we should use LDLIBS sooner or later!