Tried Memtest86+ again? I think tests 5 and 8 in particular point out errors due to timings being too tight, so you may want to loop those. Try loosening it to 2.5-3-3-7 or so, and see if there's a BIOS update for your motherboard. Try running it at 1T, for some reason it may not like being at 2. For example, Winbond BH-5 usually doesn't run well or at all with a CAS latency of 3, just 2.5 or lower
. Every type of memory chip has its own quirks, so you're probably going to have to play around with every setting to see what works.
__________________
Main PC:
Asus P6T Deluxe, Intel Core i7 920 C0 @ 3.7 GHz (195x19, 1.3v core, 1.84v PLL, 1.3625v uncore) w/Thermalright Ultra 120 Extreme, 3x2 GB G Skill PC3-12800 @ 780 MHz, 7-7-7-21-1T, 1.66v; ATi Radeon HD 4870 1 GB @ 790/1000 w/Zalman VF-1000, 300 GB WD VelociRaptor, 4x500 GB WD RE2 (RAID 10), 3ware 9650SE-4LPML RAID controller, SB X-Fi Titanium, Seasonic M12D 750w, CM Stacker 810, Windows 7 Pro 64-bit, Dell 2007WFP
XBL/PSN/WoW: Thordrune