To answer my own question, we finally pinned this issue down to the inappropriate use of LD_LIBRARY_PATH in a set of user accounts which was causing the wrong GL libraries to be used with the nvidia drivers. It is interesting that one gets the error... Error: couldn't find RGB GLX visual or fbconfig when running 64-bit software but this error is suppressed when running 32-bit software under x86_64 Fedora 10 with the nvidia drivers. In the 32-bit case, the software runs using software rendering. Jack -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines