I have an AsRock Penrynn SLI 110db which does support DDR2. I stick in new Crucial Ballistix DDR2 PC2-800 2x1GB and it doesn't post. It starts up but no picture, no beeps or anything. I replaced it with my old RAM (DDR2 400) and everything's fine and I check the BIOS. It says its in single channel mode. I don't know how to turn on the dual channel mode and there's nothing on the lit for the mobo. So...anybody got any ideas? I did try to increase the voltage for the RAM, switched it between slots (of course I know both have to be in like colored slots to work), to no avail.