I have a Macintosh PowerBook G4 1.33 GHz (12") with two monitors:
the 1024x768 main LCD and a 1280x1024 external VGA monitor
positioned to the right of the main display. I started Columba, dragged it
to the second monitor, then quit it. When I next launched columba, it
launched in a very narrow window (but with a similar-looking height to
the previous time I had run it). I had to resize the window manually
and drag the splitter bar over to see the contents of my mailboxes.