RAM issue at First Boot?

I'm probably asking a silly question....but here goes.
At first boot up, everything goes well aside from the fact that the BIOS screen tells me the 8 GB of Corsair Vengeance 1866Mhz memory is set to 1333Mhz. If I change the frequency to 1866, the system becomes unstable, and freezes up. Is the memory bad/broken or am I doing something wrong? The operating system is not yet installed, but it will be Windows 7, 64 bit.
Here is what its installed on:
AMD X8 FX8150
ASUS M5A99X Evo

Is this something that will work properly once the OS is installed?
Please help! Thanks!

Make sure the ram voltage is set to 1.5 volts. Other than that, I'm not sure.
I found this on the Asus website for your motherboard.
"* Due to CPU spec., AMD 100 series CPUs support up to DDR3 1066MHz. With ASUS design, this motherboard can support up to DDR3 1333MHz."