Benjamin: I read your post of Dec29,2004 about modifying MXUNIT in fio.h and recompiling gcc. I have done this many times on various machines. Suddenly on a new machine my recompilation (gcc-3.4.4) produces exactly the result you describe (still can not use logical unit numbers larger than 99). I have turned off the previous gcc in /usr/bin, and I have reset the f77 symbolic link to the proper location, but nothing seems to work. Did you ever find the source of your problem? Thanks, Steve Odewahn