This is a bug we’ve seen but have been unable to explain so far… for several people, all the Java-based Gallery 2 uploaders applets and apps are crashing the Firefox browser or putting it in an unstable state, preventing us from uploading pictures.
Apache doesn’t log anything wierd. The Java console isn’t very eloquent (but it reports a few exceptions), but the browser doesn’t get to show the applications that allow uploading files this way.
There is, however, a solution, which is to have a *clean* Firefox getting to the uploader pages. This can be done under Ubuntu through the command
firefox -no-remote -ProfileManager %u
This will let you create and start another (completely clean) session of Firefox, and this (in turn), will let you use the Java-based uploaders.
Another great solution would be to have FireUploader (a Firefox extension) support Gallery 2 uploads (probably trivial to do).