Simply, the computer doesnt post at all if I fill both ram slots on an Asus M2N68 AM+ board.
Ive tried 2 different pairs of ram (2x 2GB Samsung 800mhz CL6, 2x 1GB Corsair xms2 800mhz CL5) which both work in another computer.
Both of those pairs of ram are in the asus QVL so they *should* work :|.
Ive also tried 3 different PSUs just to be sure, dont have any other ddr2 ram to try.
I have updated bios to latest, dont recall version atm, Ive set the timings/clocks/voltages for each ram pair in the bios just to be sure.