Loosen tRFC. Try 55-60+.
What speed is your FSB, as in, what ratio are you using to test how far the RAM can go?
Don't try testing for max RAM 1:1 as that'll put a huge strain on the FSB.
Use 2:3; likely best option for your board.
Also make sure you have the CPU out of the picture, so run a lower multi than normal so the CPU is nowhere close to its max.
If you want some examples, i tested 2x2 GB of my Mushkin a while back just to get a quick gauge of how far they could go, & they did...
DDR2-825 4-4-3
DDR2-900 5-4-3
DDR2-1080 5-5-5
I believe i tested with around rated 2.05v for all that.
It's far more of a PITA to get anywhere with 8 GB.
I can run benches @ DDR2-1125 6-5-5 with 8 GB, but it's not stable, & actually getting anywhere over DDR2-1000 with 8 GB is a PITA to get HCI Memtest/LinPack stable when at the higher FSBs i'm running my quad.
Oh yeah, don't rely on P95 for RAM testing; it's not good.
Use Memtest86+ test 5 for quick testing; then run HCI Memtest in Windows or LinX @ max or near all RAM to confirm stability.