>I set step on and looked at the form and form vars via the debugger in the "locals" window and everything looked fine
>
>It happens on every PC that I can find, WinNT4.0, Win95, Win98, My boos says that it doesn't happen on his pc Win98, but I haven't seen it so I don't count it

Stephen,

I got another hunch;
What you describe can happen when you print "illegal". I mean, there are situations where something's eating the memory in such a way that VFP formally recognizes this one one hand, but can't deal with it on the other hand. This is the situation where the warning-message "Memory is low - streaming output is disabled" occurs. If you ever receive this one, this is it and we can talk about this further.
If you do not have this one, IMO it can be the same problem, not caused by "illegal" printing, but with the same effect. There just exists something that behaves like this, that's for sure.
General question : did you print something during the session when it happens ?

You can try another thing too;
Put a Inkey(0.1) right before the place where you suspect it starts. I mean, somewhere in the Refresh or whatever, but try to avoid to put in in the Activate. If this solves the problem, call back on me, and I may have the solution (better : cause).

Peter