Some something I want to lend about this issue;
JavaScript is not the same thing as Java. They are two completely different subsystems in a browser. Typically, browsers ship with their own javascript engine implementation. This is not something you can normally reinstall or uninstall without uninstalling/reinstalling the entire browser. Java is a VM (Virutal Machine) and is run by a browser through plugins.
I've verified that image upload (avatar, personal, desktop) for the forums, impulsedriven and joeuser are working for IE6 (excluding impulsedriven), IE7, Firefox 2.x, Firefox 3.x, Opera and Safari. I'm updating the message today which displays if the upload failed to initialize. It was failing to display the correct minimum version number. The minimum version of flash which you need installed is 9.0.28. If you dont have that version, I highly reccommend that you update. It seals up several nasty security holes.
Followup;
I uninstalled Flash completely from my system. When I visited the Account Images page, I was greeted with 'Upload has not initialized properly. Flash v9.0.28 or greater is required.' Which is the correct behavior. When I then installed flash, I was able to use the page properly.