There are lots of reasons this can happen. Try reading through the FAQ stickied to the top of this forum. Specifically here:
http://yabb.jriver.com/interact/index.php?topic=10029.msg221205#msg221205Some stuff to check:
Anti-Virus applications, Hard Drive DMA mode (vs. PIO), bad sound card drivers, and faulty memory. There are lots of other potential reasons it can happen as well. Usually, this problem is caused by something external to MC and can't be solved without addressing the root cause.
However, for some stuff to try from within MC, try:
1. Tools --> Options --> Playback --> Audio --> Output Mode (try both Wave out and Direct Sound)
2. same place, click Output Mode Settings and increase the buffering (drag the slider to the left).