Problem: UD4h + Hyper X Frying RAM!!

I need serious help. Check the system in my Sig real quick. That one is perfect. I built another one using all the same parts. The only difference is the Motherboard, the new one is a UD4H but it has the same chipset SB750..

I CANNOT run the PC8500 Kingston Hyper X at 1066mhz with this new board. This is important so make a note of this, I sent back everything except the CPU and I still have the same problem. When I received the new Mobo and RAM, I decided to leave the RAM at the default settings, all except the Voltage which I did bump to 2.2volts (Kingston calls for 2.3v but I wasn't over clocking it) So at the default settings of 800mhz 5.5.5.18, I was able to install XP Pro SP3 (same exact O/S used the first time, same install disc)

Basically what happened was, about 2 hours in one of the RAM sticks died on me. It won't even register anymore. I confirmed this by swapping the Stick into the system in my Sig which performs flawlessly. The stick wouldn't register in that machine either. I have tried playing with memtest86 but I cannot change the timings of the RAM. It's only testing the RAM at super slow speeds. The RAM did initially pass memtest on the default settings.

What are the odds of me getting 2 sets of bad Hyper X back to back like that? With a new Mobo on top of it? Someone said maybe I'm over volting the RAM but I'm not going over Kingstons specs. Unless or course, 2.3volts is too high for 800mhz. Either way, why can't I run the RAM at 1066mhz? I set the BIOS (F3 + F5 I tried) the same as my UD4P (f5) 5.5.5.15 2t 24.

I should point out this new X2 550 is running stock 2 cores. I did try to unlock the disabled cores like my first 550 but it wasn't happening. So ACC is turned off for this one. I'm starting to get worried the memory controller in the CPU is no good. Any ideas?

1 quick thought.. This new system has a HD3450 Dell system pull Video card. Is it possible the Video card limits the performance of the RAM? I tried running Hybrid crossfire with the on board HD3300 but It just won't work. The on board video comes up saying "VGA mode not supported" after the post, then eventually windows pops up. So it skips the XP start up screen? The dedicated card seems to run fine. One of many issues.