quote:fails saying the server has attempted to redirect you
I've seen that or a similar error some months past in doing some tests with Firefox on Linux Fedora. In order to finish correctly, there is a page change from the uploader to the Manage Images page with a status message at page top. I found that the Firefox Fedora version required a special setting to allow the page switch.
Look at Firefox settings: Tools - Options - Content, and click the Advanced button for Enable Javascript (which should already be checked). Try enabling the "Raise or lower windows" for a test.
Danno