Safari users can't upload to my site.

After checking through the forums, it seems like quite a few people are having problems uploading files with Safari. I have a website that I want people to be able to use no matter what browser they are using. People are able to upload files (photos and mp3's primarily) using Firefox on Mac and any browser on a PC. General computer users seem to be happy only using the browser that comes with their machine. This means my site needs to work with Safari, and it's not working for anyone with Safari so far. I think our server is Apache Tomcat 5.0.30. Does anyone have any solutions? Is this a common problem?

Should I link my site? Am I allowed to?

Mac OS X (10.4.7)