Some mp3 audio files do not open in iTunes and do not transfer to iTunes when I try to drag and drop them. They don't open or play in QuickTime or Windows Media Player either. The only way I can play them is by using LimeWire Media Player. If anybody knows why this stuff happens - please let me know.

Since you're posting in the OSX forum, I'm assuming you do indeed have OSX, right (I could, be wrong)? Well then, select one of these files and press Command-I. From there, click the little triangle to the right of "Open With" try changing the default opening application.
Ah, but before you do that, check if it is indeed an mp3 file (if that is indeed it's extension)

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iMac G4 OSX 10.3.9
RAM 256MB
LW 4.10.5 Basic
ADSL anything from 3 to 8Mbps/around 1024kbps

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