K--clueless is right about Acq and its forum, but sounds like you have two versions of iTunes installed. Just click on one of your mp3's in the Shared folder from the Finder (not in the limewire library pane) and Get Info (cmd-I) like he said. You'll see an option to "Open with", and browse to your OS 10 iTunes. Looks like the Get Info is mapped to "Open With" your OS 9 iTunes.

Secondly, do you know about "Safe Boot" and "Repair Permissions"? Here's a link for general OSX troubleshooting. http://www.macattorney.com/tutorial.html. If you've only had your Mac for a few months, you should still be eligible for free phone support.

(ps clueless--if Acq .9* is crashing for you, was it the version based on 2.9.10 or 2.9.8? One of those LW cores crashed pretty often for me uless I ran as a leaf).