Your M10000 draws most of its power from teh 5v rail. Teh HDD is likely pushing the 5v rail over The M2ATX's limit. Try powering the drive in some other way, if at all possible.
Just got a few things together. I have an Epia M10000 and a Seagate 3.5" 300gb. If I connect the m2 to only the motherboard, it starts fine. If I attach the hard drive to the m2 though, my motherboard keeps shutting down and trying to restart. Kinda like it's not getting enough juice. Anyone know of a solution to this? Thanks.
Thanks for the reply but I figured out the problem after a few beers. I was using a regulated DC power supply that could only provide 2 amps. I hooked it up to the car battery and it started up like a charm. Thanks again though.