Drop-down menu bug makes menu disappear when you are ready to click on it

bug: If a user pauses the cursor on the first (top) item of a drop down menu for more than a second, the menu disappears when he moves the cursor again. This does not happen with other items on the list.

The problem does not occur with items on the first sub-menu but does occur with the sub-sub-menu.

As can be imagined, this is a turn off for visitors to the site, who feel frustrated by the menu disappearing after the have spent a second or two perusing it and then have their cursor disappear as soon as they start moving it to their choice.

For example of problem, see: http://adhd.wallyhood.org/treatment/

Can anybody suggest a fix?