Controls on a web page are missing.

I have a customer that is running IE 7, We have also tried IE 6, and it doesn't make a difference. There are two computer side by side, and a web site that one computer can fully access and see all the controls on the page. But when you go to the other page, then you can bring up the page, but you can't see the tabs at the top of the page. When you put your curser where they should be, the pointer changes to a hand, but when you click nothing happens. I have the same java and active x installed on both. I went through all the IE settings and they are identical. I am kind of lost. I have run into this issue before on other computer, but have not been able to solve it.

Any Ideas?

Chad