I always thought that Antec earthed all of their cases by standard anyway but it seems maybe not in this case.!
The PSU is earthed as you can see in the photo: http://www.hardwaresecrets.com/fullimage.php?image=17667
The case is, of course, earthed too. You can see it if you look at the top of the case, on the right of the top fan.
I would disconnect the front panel of the case from the mobo and the case fans too from the mobo/PSU (leave the door of the case open to facilitate the ventilation during the test), and start the computer using the start button of the mobo. Please, don't disconnect the cpu fan.
If it works, in my opinion, the problem would be the case. Then I would start conecting things trying to locate the problem.
I'm just rambling. It can be caused by many things.
I would try to disassemble and reassemble everything for discarding mounting errors.