This is not meant to be a rant, it may never happen again or to someone else, but I just had a glitch happen that I thought worth sharing because it brought up a design issue that I had not though of before.
I am setting up a new WP install (A) for someone, was in admin area and things were not responsive. Also, at the same time had another WP admin area open (B), both on the same server.
Done, I found I could not log out of A. Reason being that no rollover elements in the admin panel were working. They were working in B. I disabled all plugins, tried reinstalling via the UI several times, no way to log out. When I clicked Page Content tab, Help tab vanished.
Eventually I found that the elements did temporarily work when the page was loading, so managed it that way, and logging back in resolved the issue.
My point here is that something as important as logging out should not be rollover-dependent. There is a lot of space on the dashboard to put a Logout button.