GA-890GPA-UD3H & F3-12800CL9D-4GBRL Not Playing Nice

[Binks]

New system:
Mobo: GA-890GPA-UD3H Rev2.0 FC rev BIOS
Memory: F3-12800CL9D-4GBRL
CPU: Phenom II X4 955 BE C3
HDD: WD1002FAEX (1 TB)
OS: Win 7 Ult 64 bit, Ubuntu 10.04 AMD64

The problem: Lots of BSODs related to memory issues, refusal to boot into ubuntu.

Memtest reports errors starting with test 5. Windows memory diagnostics also reports memory issues.

First set up system and set bios to optimized defaults (1333, 9-9-9-24). Problems started appearing shortly after first boot. Have spent hours scouring this tech support site to see if there is anything helpful to be tried but so far nothing has worked. For example swapping the sticks, and swapping them into slots 3 and 4.
Gigabyte tech support (after much waiting) suggested that I try running starting at 1060, but that barely even got me past boot on windows and froze during boot in linux. There is a possibility that the timings were off, since I relied on the mobo to automatically set those. In any case, no matter what settings I have used, memtest reports errors.

Is it time to RMA these, or is there something else I should be looking at?

[GSKILL TECH]

Try each stick at DDR3-1333 8-8-8-24 1.50V, to see if one may be defective.

Thank you
GSKILL TECH

[Binks]

I haven't done the individual test on 8-8-8-24, but keep reading...
I noticed that other users were having issues with cold boot, so on a hunch, I simply set the timings to 8-8-8-24 and ran memtest through 10 passes. The computer had been running for over 24 hours, so there were no errors. Booting into Linux was not a problem and there were absolutely no stability issues in Windows.
This morning (after the computer had been off overnight) I ran memtest and as soon as it reached test 5, the errors started piling up. I tried booting into Linux with no luck. After going back to memtest and letting it run for 20 minutes, I was able to boot into Linux just fine.
It appears there is a cold boot issue... Just one question: is there a way to rule out problems with the memory controller, or is it unlikely that that is the issue?

[GSKILL TECH]

If the memory controller is defective, you should have consistent problems. The fact that the problem comes and goes, makes it more likely that the memory is the culprit.

Thank you
GSKILL TECH

[Binks]

I tested the sticks individually as you suggested (1333 8-8-8-24) and one of them indeed racked up several thousand errors in memtest over three passes.
Based on previous experience, shouldn't it have stopped giving me errors after some time? Just curious...

[GSKILL TECH]

No, sometimes it can throw thousands of errors. Simply send it in for new replacements and the new set should work fine.

Thank you
GSKILL TECH