>>Does the memory come back if you release and reinstanciate the VFP COM objects?
>
>I don't know and that would be extremely hard to test in this app. What I have been testing today (left running the last 3 hours to get some real data) is what happens if I run with those objects built in instead of COM.

That should at least tell you the same thing - is the leak because of the COM interop or is it something else. Are you using GDI+ here? If so, it could be leaking memory there.