Comment 2 for bug 385399

I followed Rodrigo's instructions above and used Opera 10 Beta 1 as my default browser to try to reproduce. I was prompted for my login, then asked to "Add This Computer". After clicking "Add This Computer" I received the following error page:

"A page on the public Internet requests data from your computer. For security reasons, automatic access is blocked."

I did a search for this specific message and found several Opera forum threads noting that since Opera 9.5, the browser will block calls back to the localhost as a security precaution.

http://my.opera.com/community/forums/topic.dml?id=259892

As far as I can tell, the best workaround is to either use an Opera version prior to 9.5 or a different browser to complete the Ubuntu One setup process.