1349: Empty square when expanding main menu [#7380]

[gege]

Build 1389 with Pulse skin, in Win XP.

With "View > Main Menu bar" turned off, there's a glitch while clicking 'Menu' item, to expand the Main Menu.
How to reproduce:

1) Just place mouse cursor over 'Menu' item. Nothing wrong here:


2) Press and hold 'Menu' item. You'll notice Main Menu is in fact expanded, but also an empty square shows up below 'File' menu item.

[nohitter151]

already reported:
http://www.ventismedia.com/mantis/view.php?id=7380