This doesn't seem to be a css issue as such but I think the problem is that this iframe is causing the page to scroll to the iframe.
<iframe src="https://docs.google.com/file/d/0B77nbFQvHyu3cmswanhRelZPSXM/preview" width="300" height="250"></iframe>
If you remove that iframe then the page doesn't scroll.
You could try adding a script in the head of the page to force the issue.
However I don't think that's a best practice so I'll move the thread to the js forum for a better answer.