Every time I open Thunderbird on Ubuntu Lucid it opens as a tiny window (maybe 2px wide by 15px high) in the top left corner of my desktop. When I expand the window it's just blank. The behavior started after I restarted the application because every time I sent and email it would open that same blank little window.
I fixed this once by opening the profile manager ($thunderbird -ProfileManager) and recreating my profile.
Does anybody know what could be causing this? I can't really find anybody else with this issue on Google.