Noticed they do not work on my 0.7.2 atm
I've enabled topic thumbnails? and file upload (mite help reproduce the bug)
should prolly also mention topic thumbnail upload file option gave me this nice big red error message something to do with MSIE i think
Those errors usually mean websockets are not proxied correctly, make sure your nginx setup is correct. If you are using cloudflare you need to disable acceleration. They don't support websockets on smaller plans.