I use Mac OS X. When I try to download limewire it says it completes in a second. When I try to open it is says the stuffit manager doesn't recognize the header format. Anyone know what I can do?

I am not a MAC user - but you could see if there is a later version of stuffit - the problem may be that you are out of date and the .SIT file uses a compression format that your software no longer recognises.

You could also try deleting the file and re-downloading it. If you post the size of the downloaded file here - someone will be able to tell you if you have the complete file.

Mark