Comment 17 for bug 435805

Okay, I stumbled upon a workaround when I added Startup Manager to my computer. It added an icon to the Systems>Administration menu and in the process, expanded the panel that holds the menu items. Now it works as it should.

It looks like the problem is that the panel doesn't always correctly calculate the number or rows. To test this, I added a few extra folders to my Files & Folders menu and it also worked. So we can "fix" the problems by adding (or subtracting) menu items as needed.

If your Files & Folders menu has a faulty display, simply open a File Browser and drag some folders to the lower half of the "Places" menu in the side pane. Or you could remove folders if you like. This should work for any of the menus

http://ubuntuforums.org/showthread.php?t=1320790