I have 2G of 2x 1066 OCZ OCZ2N1066SR1G and wanted to run at 1:1 with the Q6600 but it always failed no matter the setting of the bios.. 667 was the top stable speed.
The problem is HEAT. If the northbridge gets over 35C then it will flip over.
The solution is COOLING. I went to the store and landed Thermaltake Exteme Spirit II for the northbridge and Zalman ZM NBF47 for the southbridge.
My DIMMs have EPP so I can run them on 1066 with up to 2.3V.
In the BIOS:
In extreme overclocking >
Choose MANUAL overclocking
At the FSB ratios screen choose LINKED 1:1 (or whatever you seem fit)
Better set the memory timings manually, mine are 5-5-5-5-15-22-2T
You can safely enable anything where the talk is about Virtualization and Enhanced Speedstep...
Choose any CPUOC at SLI READY MEMORY. I chose MAX.
Presto.! Runs smooth and fast and the BIOS / Sandra / Everest will show 1066 and 17G bandwidth.
Curiously, I benchmarked the memory read/write/copy/latency before this mod and had
6779/4867/4954/78.4 respectively and afterwards
I got 6970/4866/5395/67.4 which is an improvement of sorts.
Watch the stock cooling turned away but left intact - if you will need to RMA this board they will only accept it if its in its original condition, into which you can revert quite easily if you save everything that you remove.