Hi,
Is the DC too highly loaded, and unable to respond quickly enough to the DB requests. i.e. this combined with the VPN causes the DB to timeout, causing the c0000005.

It is not a good idea to run apps on a DC especially in a larger organisation.

Run Filemon and look at the response timings.

>Yep. Looked at that, and didn't find anything that seemed to apply. The thing that has me puzzled is that the program works OK as long as the files are being hosted on just about any other machine except the domain controller. When hosted on the domain controller I'm getting the C0000005 error, and it seems to be on forms that use the COMDLG32.OCX control (forms that don't use the control seem to work OK).
>Only other factor I can think of (that I forgot to mention previously) is perhaps it might have something to do with a VPN connection (which I presume is the case, as the server is not in the same location as the workstation). We've had customers with VPN connections before, though never had this sort of problem (though we did experience issues regarding speed due to limited bandwith).