It's a problem with the toolbars. They are not standard GTK+ toolbars. Once
things are switched over, then they'll resize smaller correctly.
[ 1469554 ] fixed length toolbars prevent working on narrow screens
http://sourceforge.net/tracker/?func=detail&aid=1469554&group_id=93438&atid=604306
It will probably get addressed after 0.44 gets released
And... when is that likely to happen?