Don't know if this is the right place but...
In the standard Dark orange Theme, theres a little error regarding related products in styles.css...
Line 716 reads:
.product-details-page .picture{float:left;width:300px;margin-top:25px;margin-bottom:15px;}
So the pictures are "falling out" of the surrounding box...
Should be:
.product-details-page .picture{float:left;width:200px;margin-top:25px;margin-bottom:15px;}
Easy fix...
Cheers...