iCal, iSync, and .Mac freezing issue

I have iCal syncing to .Mac every hour using iSync (so my laptop and desktop stay up-to-date). On my desktop i've been noticing that iSync hits some kind of weird endless sync. It just keeps syncing for hours and never stops and I can still get into every iApp except iCal which is "currently syncing". I'm not sure what to do, this just started happening, and there is no systematic occurance. But, I do know that my laptop that is also running 10.3 and syncing the same things never has this problem.