Mouseover changes table appearance in IE7

[Alanmelon]

Hi,

I'm currently using the Beta of IE7 as my browser, and since upgrading, whenever I visit my 4images gallery, whenever I locate the mouse pointer over tables and certain cells I get a colour change, almost like a mouseover effect. I don't get the same problem when using IE6 or Firefox, so I guess it's something to with the way IE7 is handling the style sheet. I just wondered what it could be or if I've broken anything.

URL: http://www.shoppingtvbabes.co.uk