ok, so then your comment about how they are the exact same brand/model as your last kit is null and void then? You just felt like saying it.
Moving on then to your real issue which I am now gathering is that you bought a new kit of ram and installed it to replace your old kit and thusly upgrade your available system ram.
However, this RAM only works when plugged into the A2/B2 slots and not the A1/B1 slots.
It's possible that the sticks are bad. To check this, switch back to your old kit and see if it'll boot using those while in the A1/B1 slots.
If so, further check that the sticks aren't bad by removing the old kit and putting in the new kit and restoring BIOS to defaults.
If that doesn't work, it's bad sticks perhaps.
If your old kit doesn't work now that you've put the new sticks in, then the slots on your board just went bad most likely. Still, doing a CMOS reset to check won't hurt.
I'd like to make note of this since there are many out there who don't know, but when unplugging, or plugging in anything inside of your system, it is best to always flip the switch on your power supply to off then press and hold the power button for about 10 seconds to drain any residual electricity from the system. Not doing this will leave a current running through your motherboard and components, and in the case of removing and putting in sticks of RAM, this can leave the possibility of a short happening when removing/plugging in RAM sticks which can either mess up the stick, mess up the slot which they were being plugged to, or both.