Umm...OK, I made the title overly descriptive...anyway, I stole this from here:
The MSDN facelift (not MSDN2) hosed the formatting of code samples in Firefox and Mozilla browsers. To fix it, add this to your userContent.css file (chromEdit is the easiest way to modify this file):
/* Microsoft MSDN code stylesheet */
pre
{
white-space: pre !important;
}