Are you using WLM 2012? Do you have the reading pane turned on or off?
I have just had an instance where I started up WLM 2012 (and I have the reading pane turned on) where when I tabbed to the inbox list I got nothing but "pane" when it first landed on it and the focus was actually shown as on the whole pane itself rather than a message in the inbox. Once I tabbed then Shift+tabbed things went back to normal.
I have not, as yet, been able to replicate that "entry behavior" when I shut down WLM 2012 and restart it. I have not restarted my machine to see if that has anything to do with the "pane" announcement.
It's a PITA when you encounter stuff like this but can't figure out how to "force the issue" again. Developers can't fix something they can't make happen so that they can figure out why it's happening. If you've experienced a pattern with when this happens that would be useful to know.
I don't find an uninformed hatred a "principled position" that I need to respect in any way.
~ Ellen Evans, soc.motss, 11/6/2004