today U1 started to throw an error when trying to connect.
At first I got a rather cryptic message (something with AUTH_FAILURE maybe?) upon which I found the following instructions: https://wiki.ubuntu.com/UbuntuOne/FAQ/WhatToDoWhenAuthenticationFails
Because none of the 3 possible causes described there turned out to be the case, I decided to remove my computer from the list of authenticated computers. Login into the U1 account online and removing the computer was no problem but U1 still did nothing. Finally with the instructions on https://wiki.ubuntu.com/UbuntuOne/FAQ/HowDoIAddMyComputer I finaly got U1 to re-initiate the login/auth process...
But it kept failing to connect this time showing me the message: "An exception representing an authentication failure"
So I decided to reset my password just to be sure.
Still, U1 does not connect, showing me the same message :(