CSS Image Rollovers won't Revert Back

I am currently working on a site redesign for the place I work at and am using a right-handed image rollover menu that is CSS driven. Basically, the idea behind it is that there is a transparent gif with a background applied and when hovered over, the background is swapped. This works perfectly in Firefox, but in IE, once a user hovers over the image, it doesnt always revert back. Any ideas are greatly appreciated as I have had my brain working overtime to no avail.

Temp Site URL: http://oregonstate.edu/~viehdorm/SpaceGrant
CSS: http://oregonstate.edu/~viehdorm/SpaceGrant/CSS/Master.css

IE has a problem changing the img on a:hover it needs like a :hover color before it. IE likes the psuedo classes in a certain order. LoVe/HAte
I think it would be a lot easier if you just changed the background image for the anchors rather than trying to change the image. Read this (http://bonrouge.com/br.php?page=rollover3).

I will give it a shot. Thanks for the ideas.