No table. The pulldown boxes and the button are in a single form which is "in" div tags from the rounded corners mod. I would be OK with all elements of the form being centered in the box if that makes any of this easier.
Here is the part of the CSS file that Firebug is saying the form is in.
Code:
div.xboxcontent div{
padding: 0 4px 0 8px;
}
* html .xboxcontent {
height:1px;
}