In customer/main/buy_now.tpl I found this little gem:
<div class="button-separator"></div>
only because I changed the position of the Buy Now button, so that it was on the right, not the left, and wondered why the 'Add to Wishlist' button had a space to its left, which wasn't a margin - Firebug revealed that it was A DIV!
I find this truly bizarre - that a company the size of Qualiteam, with so many talented individuals who obviously know the insides of X-Cart like the back of their hands, who can deal with the most complex server issues with no problems, haven't even got one person among them who understands the very basics of CSS - i.e. how floats work, and how margins work. Result? The entire 'CSS' version of X-Cart is a bloody mess and you will find yourselves tearing your hair out as you try to edit it all, and wonder why on earth they did it the way they did.
Sorry, I just had to vent.