Help with Dual Channel

[fluffypuffy17]

Ok guys, this dual channel thing is pissing me off, I read like every forum and can't find anything. I am running a Biostar TA890FXE, which supports dual channel dimms. I got G.skill ddr3 1333mhz ram, 2 sticks, each 4gb. My manual says to enable dual channel, have the sticks in A1, and B1, or A2, B2. The A1 is next to the B1, and the A2 is next to the B2. I tried them in A1 and B1 ( same colors right next to each other), but it wont boot. All my fans run, but the little bios code screen is popping errors like C7. When I try it in A2 and B2, SB error comes up on the screen. I have no display, no power to keyboard/mouse. However, when i put it in A1 and A2, it boots and i do everything properly. However, this does not enable dual channel. I updated bios to latest, tried un-ganged and ganged modes, but nothing will work. The last thing i want to do is RMA my mobo, since i already have everything connected. Help me please!

Here is to visualize my setup.

A1 | B1 |A2 |B2

 

[fluffypuffy17]

Ok i tried the ram slots alone and b1 and b2 do not boot alone, bad mobo?