Memory Questions

Hello everyone, I am new to this forum, so please be gentle . Recently, I just purchased a new computer. Here are the specs:

CPU: Intel Core 2 Quad Q6700 Kentsfield 2.66GHz
Motherboard: ASUS P5K DELUXE/WIFI-AP LGA 775 Intel P35 ATX Intel
Memory: 4 Sticks of Patriot eXtreme Performance 1GB 240-Pin DDR2 SDRAM DDR2 1066
Video Card: EVGA 640-P2-N821-AR GeForce 8800GTS 640MB 320-bit

Everything seems to be working okay, but the problem is, I can't get the memory to run at 1066 mhz. If I have it set to 800 mhz in the bios, it runs fine, but after setting 1066 mhz, memtest detects dozens of errors. I have tried setting the memory to recommended settings which are 5-5-5-9 and 2.3V, but memtest still reports errors. I wonder if this is an issue with the motherboard or the memory. I read that other people have gotten this memory to run at 1066 mhz. The memory is not supported by the ASUS QVL, but I have also read that other people have gotten unsupported memory to run at 1066 or higher. Any help on this issue would be greatly appreciated. Thanks in advance.