[MlMt] Ghost messages in message list pane

[Eric Sharakan]

This is an odd one.  Running r5460, every once in a while when switching 
mailboxes, a message from the swtiched-away-from mailbox remains in the 
message list pane of the new mailbox, alongside the messages from the 
new mailbox.  If I subsequently switch away from, then back to the new 
mailbox, the phantom message is gone.

I wish I had more detail to report.  I've seen this about three time 
over the last week to so.  I have never tried to select that phantom 
message.  The most recent time (just now), I was switching from a 
submailbox of a smart mailbox in one account to a submailbox of a smart 
mailbox in a different account.

Is there any more information I can capture the next time I see this to 
help debug it?

Thanks.

-Eric