I just bought 2 sticks of 512mb pc3200 ddr memory. They are exactly the same type of ram. My mobo is a gigabyte GA-7N400-L in the manual it says it supports dual channel. Ok so it says to put the two modules into slots a and b. there are four DDr slots total numbered DDR1-DDR4. Slot A is DDR1 and DDR2 and slot B is DDR3 and DDR4. Ok so i install the two modules in DDR1 and DDR3 and when i try to boot, it makes a long beep and doesn't boot, this means memory problem. So i took out one module and tried booting with one in DDR1, works fine, take that one out and put the other stick in, works fine. So the memory is ok. So next I try to use non-dual channel by putting both sticks in the A channel (DDR1 and DDR2) it boots and detects over a gig of ram like it should but after the bios screen it freezes, it will not load windows. If someone knows whats going on here i'd sure appreciate some info.