ram upgrade problem error

I have a springdale motherboard pentium 4 desktop

i was having 2x RAM of 256mb=512mb RAM ddr1

now i upgraded to 2x RAM of 1gb=2gb ddr1

now the problem is:

it is not running on dual channel (specification r same to same and brand also freq, timing, vltg etc.

only running on single channel with problem blue screen memory dump error but another RAM is not working.

with my old 2x 256mb all working great now what should i do need to setup in bios

1gb ddr333 DIMM 2.5-3-3 same to same x2 (transcend brand)

need help now!!!