>I have an application where the client can do a specific set of events, runs a particular report, then runs a particular
>data entry routine and everytime he gets the "This application has performed an illegal operation...." message
>and must reboot. It is a peer to peer network. I cannot duplicate the error on my standalone system at my office.
>If he runs the data entry routine without running one of these reports (there are four or five that cause this)
>first, it works fine. Any ideas on why this error is coming up? Help would be greatly appreciated.

If he is printing reports to an HP printer using an HP-written driver, try replacing it with an MS-written driver (for the same printer or equivalent) from the OS CD. A lot of the HP drivers are buggy and cause these types of errors.

In case you're not already using it, VFP6 SP3 made VFP more tolerant of these types of faults.