Same here.
Couldnt boot with memory @ 1600 at all
Booted right away @ 1800
Now have sended them back and get my new kit (same OCZ 1600 EB) in a few hours (the mailman is on his way)
Will report back when i tested them.
Whole my life i have bad experiences with OCZ memory, but damn, they are so much cheaper than other brands.
I stil like GSkill and Corsair best, if this time the OCZ fails, i go with one of them.