The Flash attachment uploader gets stuck at 100% when using a socks proxy.
- Set up your browser to use a socks proxy. If you run OSX or linux it is easy to test on your own computer: http://www.mikeash.com/ssh_socks.html
- Click Upload a File.
- Observe the progress bar getting stuck at 100% and not letting you embed or having the attachment show up at the end of the post.