CSS Question

The XHTML page Im building uses CSS. In the body tag Ive changed the look of my scroll bars... Its working on the parent page but the in child-page (viewed through an iframe), Im getting the windows default scroll bar but I cant find any errors and I havent made any changes to my CSS file. To make matters even more frustrating, before it was working just fine. I dont know what I could have done to change that.

:confused
Has anyone every encountered this problem??
Why do you think this is happening??
What can i do to fix the problem??

 

It may be you need the child page to have the CSS in it also?