I've updated to the latest rawhide yesterday with this problem amongst others: To reproduce: -add a clock applet to your bottom panel -set it to only display the time, not the date -hold cursor over clock and wait Expected results: -tooltip with its bottom located above the panel / clock showing date Actual result: -tooltip with its bottom aligned with the bottom of the screen, covering the mouse cursor, resulting in a fight to be on top between cursor and tooltip, which results in annoying flicker (and me not knowing the date). I've also filed this upstream: http://bugzilla.gnome.org/show_bug.cgi?id=457984
This was actually a gtk bug, which has been fixed by a recent rawhide gtk update, closing.