It sounds like a software problem. What other files are in the System
Folder? Try removing any added INITs (screen dimmers, sounds, mail, menu
clocks, and the like). It may be that their software is fine, but when you
combine this particular version of the system software with this particular
version of Xpress you get a bomb. Make sure you are using a simple System
Folder and the current versions of all the software.
Whenever you are troubleshooting a problem, always try to eliminate as many
variables as possible. This would include eliminating third party hardware as
well as any INITs or third party software that could affect the system folder.
Also, check with the software manufacturers for information on latest
revisions, what version of the system should be used with what version of
the application, and incompatibilities.
If problems continue after all software situations have been explored, look
at hardware, particularly memory or memory management. The problem could
be with RAM or the logic board.