Assuming there was nothing wrong with the MP3s (dig through the FAQ for a post on MP3 checking utilities), and assuming you weren't sitting on the Pause button on the remote, then it sounds like hardware trouble, such as a disk drive or RAM problem.

It's also possible that a piece of third-party software such as Displayserver could have been claiming too much memory. Were you running Displayserver (or anything that uses a custom init) by any chance?

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Tony Fabris