Product Attributes and Payment Textfields distort when scrolling

[russorock]

I recently built an oscommerce site for a client, and when I view the site and click on a product, the attributes that are listed underneath the description (the drop downs) look fine, but if I scroll down to the bottom of the page, the second I start scrolling the dropdowns distort, sometimes diappear. I have tried this on several different browsers, and on Safari, and some Mac's with Internet Explorer, it seems to work fine. So, I'm not sure if its a browser issue, or what? Has anyone had any problems with something like this before?

 

You can see what I mean at www.babyago-go.com

 

thanks in advance for any help you can give me...