Comment 8 for bug 1002606

jedit/compiz issue has probably been happening for a while, several users I've heard from were former gnome-panel users where the bottom panel would either initially or quickly block any further drop

Just to further mention from the benefit perspective of something containing any window - I've noticed on new installs a couple of windows always open off the Ws by default, usually the bottom.
Thunderbird comes to mind as one I always have to resize by manually moving up to get at the bottom edge/corner