Sound distorted when tracking (PT 8.x)

Hello all



Lets say I've got 3 tracks recorded (guitar, bass, keys). When I go to record the drums I can play back along with the other tracks and it all all sounds groovy. But when I activate the drum track for recording and hit "Record" the drums now sound a bit distorted, kinda like they are being double tracked.



Any ideas?



Thanks





(Im on Pro Tools 8 - PC w/ Windows XP - XBox Pro)