Hi Gary,

right now my current hypothesis of what's going on is: When VFP paints the controls something causes an exception jumping back to some outermost exception handler. Basically, VFP would stop painting. To verify this hypothesis, you could let your application run in the Visual Studio debugger and before doing so enable all exceptions on the Debug > Exceptions dialog checking the "thrown" column.

It might be a division by zero exception. In this case, you could try to add the following code to the Init, Activate and Paint event (and maybe some more places):

Declare _fpreset in msvcr71.dll
_fpreset()