P8H61-M LE memory problem

[Elma]

Hi just bought this mobo asus P8H61-M LE and its only working with one memory module
I am using corsair twinX 1333 memory

Regards Alan

 

[Elma]

it appears that if i put any stick of memory in socket b1 it will not boot but it will but if you put the same memory stick in socket a1 it boots just fine