C# ASP .NET fileupload control problems in Firefox and Safari on OS X

I'm working on providing a web form for input to a department that needs it, but have been running into problems getting the Visual Studio .NET 2005 C# FileUpload control to work with both Firefox and Safari on Mac OS X. I've had no issues with any browsers on the Windows machine: IE, Firefox, Safari, and Chrome. I've narrowed it down to a few things.

First, Safari 3.2.1 works. Most of the OS X users who were using Safari haven't updated their systems. I've found that the page errors disappear as soon as the latest version of Safari is installed. That's a logical first step when trying to diagnose the problem, but I wanted to state it because of what I found with Firefox...

The latest version of Firefox, Firefox 3.0.8, does NOT work on OS X with the fileupload control. However, Firefox 3.0.6 does seem to work (haven't tested 3.0.7), and Firefox 3.0.8 on Windows works fine as well.

Again, I'm using the built-in FileUpload control for C# web forms on my pages, from within the Visual Studios .NET 2005 environment. Maybe I'm the only one experiencing this, but since the odds are usually against that, I wanted to post this and also give you the workarounds I've found to this point in case you're running into the same issue. If I figure anything else out regarding the FileUpload control in OS X browsers, I'll post an update.

Update: Still no success when trying it with Firefox 3.1 beta 3. There is a Google discussion for this, which can be found here: http://groups.google.com/group/mozilla.feedback.firefox.prerelease/browse_thread/thread/16c5480e8d620842