Guess every Sonar user knows it already. Activation or deactivation, patch change or opening the VST windows while playing audio can cause audio to "dropout", pause for couple of ms or whatever you call it.
 
Question is: can you do something about it?

occide
Guess every Sonar user knows it already. Activation or deactivation, patch change or opening the VST windows while playing audio can cause audio to "dropout", pause for couple of ms or whatever you call it.
 
Question is: can you do something about it?

you can try increasing your audio buffer, but no, not really

if the problem occurs while opening up a VST's GUI I suspect it can be a video card update may be needed.
Remember a lot of plug ins now a day use Open GL (including Cakewalk plug ins). I would look for an update for your onboard/outboard VC and possibly even an Windows Update. But like PWAL, this doesn't happen to me either.
 
What are you using for a soundcard ? Are you still using that "M-Audio Delta 44" ? 
Can you post some specs ?