Hi Gregory,

From the MSDN:

Applications that do not use high-resolution timing should use the SetTimer function instead of multimedia timer services. The timer services provided by SetTimer post WM_TIMER messages to a message queue, while the multimedia timer services call a callback function. Applications that want a waitable timer should use the CreateWaitableTimer function.

If we can believe the above, the timer events queue up until VFP has a chance to process them. In your test, I suspect the Fox is getting it's britches yanked down at a most inappropriate time. I'm sure we all agree that the native timer does have some drawbacks, but I can live with that for the stability and simplicity.

>There must be a good reason why vfp saves the events and gives a burst afterwards.
>The callback fll has bugs
>
>I suspect vfp turns off timer events during critical operations (eg update). After that the number of missed events is calculated and caught up (the burst)