Please ensure you have the following DLL's on your client PC's:
SSCSDK80.DLL
SSCDLG.DLL
SSCRC.DLL
PG32CONV.DLL
AMZ14.DLL
LTKRN11N.DLL
There is also a utility on the Crystal Reports CD called Modules. This allows you to view by process or DLL which DLL's are running and where they are called from. If you double click on a DLL, it gives you the start and end address in a similar fashion to the GPF message you have been receiving. Therefore by a process of elimination, you should be able to detect the DLL taht is giving you problems.
HTH
Steve Chapman