Comment 2 for bug 575486

In my case the shutdown menu button isn't fully removed - I see left half of the button, and the right one is hidden by a blank panel, just like the last letter of your username on the screenshot. But I suppose it's the same issue - the button is not fully hidden because I've got a shorter username. I'll post a screenshot when I encounter this problem again.
Changing theme helps. Btw I had this with Ambiance and Radiance.
Ubuntu 10.04 Desktop amd64.