I have a biostar tforce 6100 motherboard(939) with 4 ram slots, and 2x512 Adata pc3200 ddr 400mhz dual channel sticks installed. I wanted to bump up to 2gigs of ram. So I got 2x512 Ultra sticks with the same numbers(pc3200, 400mhz ect...) When I put all 4 in, my computer reads zero ram, nothing. Seperately, when I put each pair in I get 1gig of ram, that is not my goal. Can some one explain what is going on and how can I fix it so I get 2gigs with what I already have?