Hi Mauricio,

As I suspected!

You have constructed a combination of objects that it triggers, in VFP8, a classic multithreaded synchronization error.

For what I have been able to understand (I have not inquired in merit), graphical regeneration comes made from a thread specific,
therefore only Microsoft can find the synchronization error that generates your C5.

In order to render you still happier, I have found a pair of these errors also in VFP7.

The more likeable thing is this:
this type of error is nearly always not determinist, it is legacy statistically to the relative time of execution of the threads, and therefore, if there is GOOD FORTUNE TO ALL!

Fabio