iframe content outside container div

[pumpkin]

Hi folks
I'm putting a page together here http://xypex.temp55.viperdesign.co.uk/wordpress and trying to import the news items from their main company via an iframe. Here is the code I am using in the widget:

<div style="width:100%; padding:0; margin:0; 
height:500px; position:relative;
overflow:hidden;">
<iframe src="http://www.xypex.com/index.php" style="
margin-top:-290px;
width:100%; overflow:hidden;
height:720px;"
frameborder="0" name="Xypex News">
Please update your web browser to view this News section</iframe>
</div>

Looks fine in IE and Safari but FF makes the iframe content start above the container div. I'm not fluent with this so you may be able to spot the problem straight away.

Are iframes still used? I tried doing it with a php include inside the div but this didn't work either, just had a blank space.

Thanks