div is getting cut off at the bottom

So I have this page and this page. Both pretty much identical apart from the contact forms.

You’ll notice that the form starts to disappear at the bottom of the div. Not too sure what’s going on here. As I add to that page it just pushes the hidden content down rather than increasing the size of the div to accommodate.

It might be these divs but might not:

#contactWrapper {

	margin-left:auto;
	margin-right:auto;
	width: 1100px;
	margin-left: -40px;

}

#contactLeft {
	width: 550px;
	float: left;
}

Any help appreciated