David,

If Session is supposed to be preserved, I have no idea what could be going on unless it concerns the rights attributed to the VFP dll. I'm using Session, not ViewState, so, as I thought, something else is going wrong.

The frustrating part is that it does not consistently happen - 8 or 9 times out of 10 it will work.

I know early on I had a problem running some of the C#/VFP interfaces. Under what secuirty context should the VFP dll be running?

TIA,
Doug