[Interface Kit] diagonal mouse support doesn't always work as expected

[diver]

Menu doesn't get selected under some specific circumstances.

• open /boot
• right click system folder
• place cursor above the folder icon
• start moving cursor horizontally to the right from the icon to letter m (as in system)
• without stopping continue cursor moving vertically down to Edit name menu item and leave it there

At this point Edit name should be selected, but it didn't, like if it got stuck on the first menu item. Interestingly, if you move your cursor the same way from system to Mount (which has a submenu) it get selected.

Probably it has something to do with diagonal mouse support #284/hrev24193.

Maybe some ideas can be taken from this research: ​http://bjk5.com/post/44698559168/breaking-down-amazons-mega-dropdown