http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55729
--- Comment #2 from pmarguinaud at hotmail dot com 2012-12-18 16:25:01 UTC --- Hi Tobias, I use gfortran 4.7.0. It was build and installed by our admin, as you can see below : $ gfortran -v Using built-in specs. COLLECT_GCC=gfortran COLLECT_LTO_WRAPPER=/home_nfs/softs/gnu/4.7.0/libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: ./configure CC=/usr/bin/gcc --prefix=/home_nfs/softs/gnu/4.7.0 Thread model: posix gcc version 4.7.0 (GCC) Our cluster is a SandyBridge with a RedHat 6.0; uname -a says : Linux login0 2.6.32-220.23.1.bl6.Bull.28.8.x86_64 #1 SMP Thu Jul 5 17:34:18 CEST 2012 x86_64 x86_64 x86_64 GNU/Linux I will try newer versions of gcc, as you suggest.