Hi, I am using fortran compilers on OSF1 V 4.0 (DECFortran) and on IRIX64 6.5 (MIPSpro compiler) to compile and run numerical routines. But running the image, I get different results if I compile the same source. I should note that I use the Fortran compiler on DEC to link the shared library statically (-non_shared) to run it on Linux Alpha as well, but I don't think the trouble lies there. Is there a way to localise the error easily ? Cheers, Marco. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%