alright i checked and both kits are supported (KVR1066D3E7SK2-4GI & KVR1066D3Q8R7SK2-8GI), Scenarios tried:
1- 6 GB for the first CPU and 6 GB for the second through Blue slots, i got beeped
2- 6 GB Blue and Black for each CPU, i got beeped
3- Both kits work separately with no problem, but dont work together, i noticed a difference in ranks, so there is my problem, right ??
I checked your DIMM specs, and noticed you're mixing UDIMM and RDIMM, which is not supported. That's why you got beeps.