Howdy,
I've been having this problem for a while with iTunes where the audio cuts in and out. When I bring iTunes up to the foreground, the time counter keeps going but no sound will be playing. I'm on an eMac 1ghz, 1gb RAM, it's been happening since before iTunes 4.2 and continues up to 4.5. I do use a few APE modules... but have turned them off and nothing changes. I also quit my folding@home graphic app and that seemed to help a little bit. Activity monitor used to show REALLY heavy processor use with FAH on. Mind you, I like to listen to music while I work on Dreamweaver MX and Photoshop.
Anybody have this problem?