Sorry, it's not quite a bug, it's more my feature request. I am
hoping to write the code to do it, and then share it.
Your current hide delay is for hiding all open menu items. When you
have autosubmenudisplay on, and you are hovering over a menu that has
a submenu, it displays, but it is not among the "all open menu items"
list, since it closes immediately when stop hovering over the menu
item. This close is done by line 1942 of menu.js, and there is no
delay on it.
It would be nice if it would stay open for some period of time.
Probably it would be a different delay amount than your current
hidedelay, since it serves a different purpose. At the most, the
delay should be the same as the showdelay. The reason to keep it open
with a delay is so you can go to a submenu without carefully moving
the mouse along the menu item to get to the submenu.
For example, in Firefox click on "View" and you see a full menu, one
of the items is "Character Encoding". Hover over it, and a menu of
eight or so items appears to the right. If you move in a straight
line from the word "Character" diagonally down to "English", you
briefly are not on the item "Character Encoding". Do that quickly,
and the submenu will still be open by the time you get to the
"English" item. Do it too slowly, and the submenu disappears.
The YUI Menus, in contrast, will always close that submenu, and to go
to an item on that submenu, you have to mover in a straight line over
the menu item to the first item on the submenu, then move down.
Once I've implemented my own version of this enhancement, I'll post
again how I did it. It's not trivial, like my "useClass" enhancement is.