Hi all, I do not want to write a long post here but I really need some enlightenment about a strange problem. My Macbook came with Tiger and Xcode 2.4. Being a Fortran programmer, I installed Intel compilers without much hassle. Then Leopard arrived but I decided to not upgrade until receiving the green light from Intel (for months their compilers were broken for first-time Leopard users). A few months back most of issues seemed to be gone (I successfully installed the new compilers on 3 Mac Pros and 1 Intel iMac) and I was able to upgrade my Macbook to Leopard and the new compilers. Here starts the drama : last week I had to upgrade my hard drive so I backup everything and did a clean Leopard install on a new and bigger HD (Hitachi 200Gb 7200rpm). Everything went fine except the fortran/C compilers. The error message I get is unique (try Google) : ifort: error fatal_error_terminated: Fatal error in /opt/intel/fc/10.1.014/bin/ifortia32, terminated by segmentation violation (I got similar message if I setup 64 bit compiler) I can not compile anything. Even a simple hello.f. I even update to 10.5.4 but nothing changed. In fact, it was so frustrating that I decided to do another clean install of Tiger. Yes, I downgraded Mac OSX to 10.4, downloaded the old Fortran compiler (the one I had) and guess what ? I got the SAME message. I triple checked my shell environment, looked over all libraries but nothing seems wrong. The ONLY thing that caught my attention was during the installation, when I selected to format the new disk using HFS+ journaled (non case sensitive). I do not believe that my old original drive had a case sensitive system but I did not checked it. If you can help, it would be very much appreciated !