Nice work, looks very sharp. However, I notice in Safari that the sub-menu doesn’t always stay visible when dropping down from the main menu to the sub-menu; kind of frustrating on an otherwise great looking menu! Any ideas of how to fix this? Would it be related to the 1px border between the main and sub-menu?

I’ve never been a fan of this type of navigation. Testing with some elderly users and the had difficulty sticking to the very narrow amount of movement these types of menus allow. You have to be reasonably precise when moving the mouse pointer along the horizontal axis. Even I personally don’t find them very usable.

A traditional sub-menu that simply lists all the items straight down is much more forgiving because they are typically wider and of course you’re only moving the mouse one direction – down. Not down and across. Seems counter productive to make navigation harder to use.

Also, and this is just this particular implementation of this menu you have in the demo, it’s not exactly the most semantic thing I’ve seen. The sub-menu items should preferably be listed like the root items are (in an unordered list).

It looks nice though.