P5KPro and memory issue

So guys, here's my problem:

Yesterday i installed my new P5KPro and with it i put also 2X1GB of Kingston HyperX PC6400 low latency modules. They are certified 4-4-4-12 at 2.0 V. I looked on the asus website and saw they were supported by the motherboard.

I tried to install also XP pro but had issues during install (BSOD). I put the the settings in BIOS to automatic and the BIOS recognized them as DDR2 667 with 5-5-5-9 timings. I took another copy of XP (this time a home edition) and all went well, installed OS etc. I flashed the BIOS and put the latest 0701 version. I went again to change the timings to 4-4-4-12 DDR2800 but when the loading screen appears the system resets. Now things go well with 5-5-5-12 timings but i'm pissed off coz i can't use them at the lowest certified latencies.

I'd like to reinstall XP Pro, but do u have a solution for my timings problem?

the rest of the specs are:
PentiumD 820 at stock (to be replaced soon with a E8400)
one SATA 160GB Hitachi
HD 3850 512MB
Corsair VX 450 PSU

thanks,

Paul

I actually tried already 2.0V and 4-4-4-12 (volts - i am a physicist so i know what that means ) and i had the same reboot problem. I'll give it a try with 2.1 V.

thank you for your help.

Run CPU-Z and look at the SPD tab.
What speed is 4-4-4-12 certified for as SPD?