4gigs causing memtest errors

[64dragon]

i just got a second kit of ddr2 6400 4-4-4-12 2*1gb and when i installed it i went straight to memtest to see if it was ok and when i run all 4gigs i get 20+ errors between the first 2 tests. i tried changing the timings to 5-5-5-12 but that didnt help. i'm currently running just the new set by themselves and i've done 2 loops of all the tests with no errors. any ideas of what i should try next?

[AlphaHeX]

Please remember that for 4 sticks you need to raise NB voltage and sometimes also CPU voltage.

[64dragon]

thanks alpha, it was the cpu voltage.