NO BOOT IN DUAL CHANNEL (gigabyte 790x-udp4 + ocz reaper 1066 2x2gb)

Hi, I recently built my own system and I am having trouble booting up with my ram in dual channel.
The manual says to have the ram in slots 1and2 or 3and4 for dual channel. But when I have them in those DIMMS they computer does not boot to post and the mobo gives a "power error" beep. When I have the ram seated in 1and3 or 2and4 for single channel, it posts and runs just fine. I have tested each stick and there are no problems with either.

Stick A alone = boot
Stick B alone = boot
Stick A + B in 1 + 3 = boot
Stick A + B in 2 + 4 = boot
Stick A + B in 1 + 2 = no boot
Stick A + B in 3 + 4 = no boot

SYSTEM:
AMD Phenom II X2 550 BE
Gigabyte MA790x-UD4P BIOS f5a
OCZ Reaper 8500 1066 2x2GB
Sapphire HD4890 Vapor-X 1GB
Corsair VX550watt
WD 500GB 7200rpm
WIN 7 RC
Full gigabyte tower

Timing of RAM set to 5-5-5-18T 2T +.3v to 2.1v @1066

I have asked on the OCZ forum and recieved no answer but I was sent RMA info from one of the reps. No attempt to fix issue.

SO to recap, I can boot the system with 2gb or 4gb ram just fine in single channel, but if I attempt to put in into Dual channel, it does not post and the motherboard beeps a power error.
ANY AND ALL help is very much appreciated. If there is more info you need, let me know and I will get it for you asap. I think I have included everything that you need. I have some a couple days of research but have come up sort of a solution.

Thank you for your time!

With one stick in, I can set it to 800 in bios then shutdown and put second stick in and it won't post.

Gigabytes qvl is pretty limited and ocz does not have a list of mobos they certify. I just matched the type and speed of the ram.

http://www.ocztechnology.com/produ [...] gb_edition

http://www.gigabyte.us/Support/Mot [...] uctID=3031

I've read reviews of the same mobo-ram set-up that worked correctly...
maybe I'll just RMA it and hope it works.

I had this exact problem with my old pc from 2005 using 2x1gb corsair XMS. I never found a solution for that either and left it run in single channel for the past 4 years. Just wished my new system would work like it should.

I know that it doesn't add to the solution of the problem but I'd like to share with everyone my personal experience that is almost identical to the issue indicated apart from the fact that my gigabyte mobo (GA-MA790X-DS4) worked fine with 4x1GB Corsair DIMM in dual-channel mode also with the latest BIOS for almost a year.
Recently, though, I upgraded the system by substituting the CPU with the newest Phenom II X4 940 AM2+ from AMD: the system worked fine with 4GB in dual channel for a couple of days then, suddenly, one day stopped working and I had to remove two DIMMS in slot 2 and 4 (but it is the same with 1 and 3) to make it work.

Any hint on this?

Thanks