Memory module compatibility question

I recently upgraded my system (new psu, cpu, heatsink, gpu and memory modules) and after failed system starts (just the fans would turn on) and some puzzling, I isolated the RAM modules as the problem. Using my old sticks my system starts and works fine. So I sent them in to the shop and they told me there was nothing wrong with the modules. Now I'm wondering about their compatibility with my system.

Motherboard: GA-MA790X-DS4

Old RAM: Kingston Value Ram 800 MHz DDR2 2x1 Gb Sticks, Kingston Value Ram 667 MHz DDR2 2x512 Mb sticks (being replaced)

New RAM: OCZ Memory Vista Performance Gold Edition DC 800 MHz 2x2 Gb sticks

If someone can point me out to the possible incompatibility and why, I'd appreciate it.

What are the required voltages for each brand at 800mhz, the system is going to set it to 1.8 but thats probobly not what either chip needs.
Try setting ram clock manually to 400 or (x 4) and the voltage to 2.0 volts