To reproduce do the following in IE7:
1. Use mouse to rollover a menu item with a submenu that also has a submenu.
2. Use mouse to rollover a submenu item within the 1st submenu (three tiers of menu should be showing: main, 1st submenu, 2nd submenu)
2. With mouse in the 2nd submenu leave it (e.g. move mouse up and outside of 2nd submenu)
3. Mouse over the main menu item
Notice the 2nd submenu displays when mouse is over the main menu item and the 2nd submenu is blank. This only seems to occur in IE7 (tested FF, IE6, and NS8 as well).