diff --git a/config/ompi_check_xgrid.m4 b/config/ompi_check_xgrid.m4
index a6102bac62..8d2e441301 100644
--- a/config/ompi_check_xgrid.m4
+++ b/config/ompi_check_xgrid.m4
@@ -51,10 +51,12 @@ AC_DEFUN([_OMPI_CHECK_XGRID],[
     # Objective C is, so in the end, we put things in OBJCFLAGS and
     # the right things will happen.  *sigh*
 
-    ompi_check_xgrid_save_CFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS -framework XGridFoundation"
-    AC_TRY_LINK([],[;],[ompi_check_xgrid_happy="yes"],[ompi_check_xgrid_happy="no"])
-    CFLAGS="$ompi_check_xgrid_save_CFLAGS"
-
-    AS_IF([test "$ompi_check_xgrid_happy" = "no"], [$2], [$1])
+    AS_IF([test "$ac_cv_sizeof_long" = "8"],
+          [ # can't compile in 64 bit mode
+            $2],
+          [ompi_check_xgrid_save_CFLAGS="$CFLAGS"
+           CFLAGS="$CFLAGS -framework XGridFoundation"
+           AC_TRY_LINK([],[;],[ompi_check_xgrid_happy="yes"],[ompi_check_xgrid_happy="no"])
+           CFLAGS="$ompi_check_xgrid_save_CFLAGS"
+           AS_IF([test "$ompi_check_xgrid_happy" = "no"], [$2], [$1])])
 ])
diff --git a/config/ompi_configure_options.m4 b/config/ompi_configure_options.m4
index 071a03f7a1..07c752e366 100644
--- a/config/ompi_configure_options.m4
+++ b/config/ompi_configure_options.m4
@@ -165,14 +165,20 @@ fi
 AC_MSG_CHECKING([if want Fortran 90 bindings])
 AC_ARG_ENABLE(f90, 
     AC_HELP_STRING([--enable-f90],
-                   [enable f90 MPI bindings (default: disabled)]))
-if test "$enable_f90" = "yes"; then
+                   [enable f90 MPI bindings (default: enabled)]))
+if test "$enable_f90" != "no"; then
     AC_MSG_RESULT([yes])
     OMPI_WANT_F90_BINDINGS=1
 else
     AC_MSG_RESULT([no])
     OMPI_WANT_F90_BINDINGS=0
 fi
+#################### Early development override ####################
+if test "$OMPI_WANT_F90_BINDINGS" = "1" -a -z "$enable_f90" -a -d .svn; then
+    OMPI_WANT_F90_BINDINGS=0
+    echo "--> developer override: disable Fortran 90 by default"
+fi
+#################### Early development override ####################
 
 
 #
diff --git a/include/Makefile.am b/include/Makefile.am
index 481be13ff3..d88940527a 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -16,27 +16,26 @@
 
 include $(top_srcdir)/config/Makefile.options
 
-dist_include_HEADERS = \
+dist_noinst_HEADERS = \
 	orte_config.h \
 	ompi_config_bottom.h \
-        ompi_stdint.h \
+        ompi_stdint.h
+
+nodist_noinst_HEADERS = \
+	ompi_config.h		
+
+dist_include_HEADERS = \
 	mpi.h
 
 nodist_include_HEADERS = \
-	ompi_config.h \
 	mpif.h
 
-# Add a hook to run *after* the file ompi_config.h has been installed
-# out to the target location.  It changes the pesky PACKAGE_* macros
-# that autoconf automatically generates (and there is no way of
-# turning off) into OMPI_MPI_PACKAGE_* in order to make <mpi.h> safe to
-# include with other files.
+# Conditionally install the header files
 
-install-data-hook:
-	sed -e 's/define PACKAGE/define OMPI_MPI_PACKAGE/' \
-		$(DESTDIR)$(includedir)/ompi_config.h \
-		> $(DESTDIR)$(includedir)/ompi_config.h.install
-	cp $(DESTDIR)$(includedir)/ompi_config.h.install \
-		$(DESTDIR)$(includedir)/ompi_config.h
-	rm -f $(DESTDIR)$(includedir)/ompi_config.h.install
-	chmod 0644 $(DESTDIR)$(includedir)/ompi_config.h
+if WANT_INSTALL_HEADERS
+ompidir = $(includedir)
+dist_ompi_HEADERS = $(dist_noinst_HEADERS)
+nodist_ompi_HEADERS = $(nodist_noinst_HEADERS)
+else
+ompidir = $(includedir)
+endif