Quote from SariashI guess that is because wowinterface.com is blocking requests when they come too fast... if you try to open multiple wowinterface.com pages in Firefox you get "Request block, This is to stop flooding of our server." on most of them.
I thought so too so I tried updating 2 addons to see what happened. Same error as I suggested before. I then waited a few minutes and tried the 2nd one that failed again. It still did not work. I then closed WUU and retried. Now it could update the 2nd addon. I then immediately reupaded the 1st addon just to check if I could be flooding the server and it updated also.
Weird things are happening :)