Nice Score, but you are sure that you are in the Motherboard limit? I think its not the Motherboard but the RAM can it be. Have you testet higher timings? Very strong cascade and nice temp.! Batch from the CPU?

Yes, because this rams may much more. 

I tested different timings, PL's and voltages of CPU and rams. CPU pass this bench at 5.85ghz with only 1.65V.

For the moment I tested only 333 strap.

Rev 1.1 or Rev 1.6 board? Though not sure when cold chipset becomes necessery on P45 yet.