I just discovered another bug in OS X Lion where windows aren’t resizing properly.
In Apple Mail, choose Preferences, then Fonts and Colors [sic]. Change your Message list font size to something large, say 48. Quit Apple Mail. Reopen Apple Mail and choose Preferences, Fonts and Colors again. The window hasn’t resized to take into account the larger text box above it.
This, combined with the other issues I noted a couple of days ago is kind of showing that Lion isn’t as polished as it could be. Come on Apple, don’t drop the ball!