--- MITgcm/tools/build_options/linux_ia32_open64	2009/06/22 23:13:30	1.3
+++ MITgcm/tools/build_options/linux_ia32_open64	2009/08/14 20:28:19	1.4
@@ -1,11 +1,13 @@
 #!/bin/bash
 #
-#  $Header: /home/ubuntu/mnt/e9_copy/MITgcm/tools/build_options/linux_ia32_open64,v 1.3 2009/06/22 23:13:30 ce107 Exp $
+#  $Header: /home/ubuntu/mnt/e9_copy/MITgcm/tools/build_options/linux_ia32_open64,v 1.4 2009/08/14 20:28:19 jmc Exp $
 #  $Name:  $
 #
 # Build options for Fedore Core 4 i686 Pentium4
 # tested on (Linux lagoon 2.6.17-1.2142_FC4smp #1 SMP Tue Jul 11 22:57:02 EDT 2006 i686 i686 i386 GNU/Linux) system 20071121
 #
+# Note: use just -O2 optimisation to avoid some wierd problems with -O3
+#       on aces (open64/4.1 & 4.2) (ideal_2D_ocean)
 
 CC=opencc
 FC=openf90
@@ -26,15 +28,15 @@
 
 if test "x$IEEE" = x ; then
     #  No need for IEEE-754
-    FOPTIM='-O3 -LNO:fusion=2 -OPT:roundoff=1:IEEE_arithmetic=3' # -funsafe-math-optimizations'
+    FOPTIM='-O2 -LNO:fusion=2 -OPT:roundoff=1:IEEE_arithmetic=3' # -funsafe-math-optimizations'
 else
     #  Try to follow IEEE-754
-    FOPTIM='-O3 -LNO:fusion=2 -OPT:roundoff=0:IEEE_arithmetic=1 -fmath-errno -fno-fast-math'
+    FOPTIM='-O2 -LNO:fusion=2 -OPT:roundoff=0:IEEE_arithmetic=1 -fmath-errno -fno-fast-math'
 fi
 
 F90FLAGS=$FFLAGS
 F90OPTIM=$FOPTIM
-CFLAGS='-O3 -m32'
+CFLAGS='-O2 -m32'
 GSLLIB='-lgsl -lgslcblas'
 
 if [ "x$NETCDF_ROOT" != x ] ; then