Build: Mozilla/5.0 (X11; Linux i686; rv:5.0a2) Gecko/20110516 Thunderbird/3.3a4pre There is a regression in nightlies, I was away for 10 days so it's not older than that. When you type in a compose window, at reaching the right edge of the compose window, the text you are typing does not flow to the next line, you just type and nothing is displayed, if you resize the window you see that the text is actually there. (Tested in safe mode) Talking to Ludovic, the following options are set to their default values. mail.compose.wrap_to_window_width;false mail.wrap_long_lines;true mailnews.wraplength;72

This is WFM on Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0a2) Gecko/20110516 Thunderbird/3.3a4pre Maybe a linux-only regression?

I think this happens if the composition window is narrower than the toolbar width.

(In reply to comment #2) > I think this happens if the composition window is narrower than the toolbar > width. Yes (assuming HTML composition, obviously). In that case, this is a dupe of bug 654754.