this is a quote from jford on another thread...............

I keep the most recent ASIO driver from Behringer installed. I generally have it set to 256 buffers, but sometimes when I have a lot of tracks, I have to up it to 512 buffers to eliminate crackle and dropouts. I have to rarely do this.

you might not be using the same asio driver - more likely it's one specific to your gear - but you could try the buffers on playback