IE8 issue had nothing to do with xcart.
http://forum.x-cart.com/showthread.php?t=64110
(scroll down)
Still having all of the other issues, but since IE8 submit works, my intensity can come down a bit.
But we are still seeing duplicate and triplicate orders submitting.
Hmm...
Customers are still confused.
Hopefully we'll find the solution soon.