Since the case and motherboard tray are at grounded to 0 volt potential assuming the powersupply is correctly installed and plugged in you have to make sure the back of the board which has some ground and some hot circuits on it does not come into direct contact with the tray. If the tray or any other part of the case is contacting a positive potential circuit path when power is applied to the board it can cause a dead shot across sensitive componeants of the board, and potentially kill ur motherboard.
Your psu has 4 +12V rails if you havn't already you should ckeck that power draw from the various componants of the system is spread as equally as possible over all 4 rails. If you try to connect the whole system to one or two rails of a four rail psu it will not yield enough power.
Also try booting up with only 1 stick of memory installed. sometimes a brand new bios needs to be booted with one stick so the ram voltage can be bumped up a touch. On my last build same type of problem just wasn't giving enough juice to the memory untill i pulled 3 sticks and raised the voltage .1v then all was well.
Just a few thoughts good luck and keep posting.
Mark
IF: x="massive overclock"
THEN: PRINT "woot"