[tryfuhl]

This is on a laptop? Do you keep it running pretty much all of the time?

Open up the task manager (ctrl + alt + del OR start > run > taskman) and while you're playing audio or streaming, check your resource usage, particularly the CPU/Processor)

what type of laptop? a lot of toshibas, hp's, etc etc overheat easily and it'll basically kill the processor from overheating, this happens mostly for people that keep theirs on quite a bit, I've seen some that got bad enough that even typing in word the computer would have to catch up to the typing

hopefully that's not it, make sure you have the audio device drivers updated from the manufacturer's website, and if they make it worse, roll them back through device manager