draff

Recording Problems-noise, Distortion

I have been searching all over the net for the answer to this problem, but there doesn't seem to be one definitive answer. Nonetheless, here's the problem.

I have an iBook 700 mhz, 384 mb RAM, 30 gb HD, running OSX 10.2.4. I run out of a Mackie CFX-16 mixer into a Griffin iMic, then into the Griffin powered USB hub, then into my Mac. I am using Ableton Live 2.0, along with Propellerhead Reason 2.0.

When I start recording takes into Live, things go fine for a short period of time. After about 15 minutes or so, takes start distorting upon playback. A sort of digital distortion that sounds like something straight out of 'The Matrix'. Also, if I try to record a take longer than 3 or 4 minutes in length, the distortion seems to be happening quite consistently. It is the entire take that is distorted, not just part of it. I then quit Live, restart it, and try again. It seems to work fine for a little while, then starts again.

I read a post that mentioned the iMic has problems as it is powered by the mac, and that may cause pops and clicks. The info, taken from the Griffin site, recommended picking up a powered USB hub. I bought Griffin's as it is supposedly designed specifically for audio recording. Even with the powered hub in the mix, though, I'm still getting distortion after a little while.

I've been playing around with output levels of my mixer, and input levels in Sound Preferences, thinking I may be overloading the sound card. I still get the distortion after a little while.

Anyone who can solve this TERRIBLE problem for me will be my hero. Any help out there?
Thanks,
Derek