I refer to this from the trouble shooting guide.

" 4-2Q. On my Macintosh computer, all my MP3 downloads appear as LimeWire documents or LimeWire docs. None of my software players can recognize these files. How can I fix this?
4-2A. Try shortening the file name and adding the appropriate extension (i.e. mp3 for a song) manually to the file name. The maximum length of a file name on a Mac is 32 characters. You can also play MP3 LimeWire docs with a program called MacAmp. Go here to download this program."

However it is not working on any file over 32 characters..which is ok I suppose. But then when I try to open a zip or sit it just doesn't work. Perhaps I will give this mactella thing a try, and hope for the best.