So, everybody knows that form input controls are under the OS control, not the browser control. IE does this "funny" thing where if you put an absolutely positioned container over select boxes, the select boxes will still render on top.
The hack is, of course, to use an IFRAME. For convenience and added hackability, we use filter:alpha(opacity=0) and z-index=-1 on an iframe positioned inside the container we want to cure. Ah, but since this is only for IE, we add some proprietary IE browser logic (--[if IE]--).
"But hold on!", you say. That's right. You were wondering why if i put a border around the container, the select boxes will still butcher the border. That, of course has to do with the crappy box model implementation, and I have yet another hack (er, workaround) for the IFRAME style to lighten your day:
border: 1px solid transparent;
That's just money.