i rma'd a 3.1gb hd way back in the day, using the advance rma thing. they sent me a 4.2 gb drive, i sent them the 3.1, its all good. the 4.2 is still in use. the 3.1gb wasnt even mine
more recently i rma'd an 80gb, and again had no problems.
also you dont need an error code. since i have an a7n8x, powermax wont work on my board (it doesnt like sata). i called them up and told them this, and explained the problem and they just rma'd it on the spot.