Scrollbar at bottom inside iFrame in Expression Web, but not in FP

[MonaLH]

I have used FP2003 to make homepages for a long time without any problems,
but then I meet a problem when using Expression Web and it is making me
crazy!!

I often use iFrame and open new HTML pages inside this. But when I create
new HTML document in Expression, it comes out with a scrollbar at the bottom
inside the iFrame, and there are no tables etc who broaden the page. BUT, if
I create a new HTML document in FP2003, save it, and then opens it in
Expression web and attach the CSS, then it works as it should, with no
scrollbar at the bottom, only at the right side when needed.

Does anyobe have an idea on what is wrong or what I can do to fix it??
Seemes so strange?