Where is my Download? .sit files lost, BUT NOT other file types
 

OK, odd problem i think. In my library under "shared" files, there is a .sit file i downloaded. On my finder (mac osX 10.3.4) window under that same location, there is no file to be found. I also did a search on my HD and its not there.
File said it was successful, limewire says its there, my .avi and .mp3 files are downloading just fine, so whats the deal?

Uh, it may be possible that the .sit file may have automatically unzipped (or unsited...) and the original sit file has been sent to the trash (or erased), but I don't remember this ever happening to me.
Anyway, try looking in the shared folder for somethng that might contain what was in the .sit file. If you can't find any, then try dlding another .sit file to see if this happens again.