Remove The Cursor Focus?

In FireFox, when one clicks on a fold and the fold expands, and if the mouse pointer is over the expanding content, then focus is drawn to each of the sub-menu items as they pass the mouse pointer. This makes the animation look a bit juddery.

In all other browsers, one clicks on a fold, focus is drawn away from the mouse pointer, the fold expands and then when one moves the mouse again the mouse pointer gets its focus back.You can see this best by clicking on the tabs "curriculum", then "admission", first in IE and then in Firefox.Is there any way to make the mouse pointer give up its focus in Firefox, so when the animation is taking place it ignores such rules as Code CSS:

.sub_link:hover{
background-color:#E8EFCF;
}

which have been applied to the sub-menu items?l would be something like "cursor.blur();" although obviously that won't work.