Bios won't let me pick 1.5, so I tried 1.53 (next level up). No dice. Also tried 1.59 and 1.65 and it didn't work.
I noticed that when my Bios opens up it states that the board is set to single channel memory mode, but I can't find an option to change it. >_<
Single vs. Dual channel is something auto detected by the BIOS based on the memory installed. You typically can't set this on many motherboards. From a practical standpoint, the performance difference between the 2 modes is largely negligible for the vast majority of users.
Regardless, there are 2 possibilities here. Defective memory (or memory controller) or incompatible memory.
Double check the BIOS version (as suggested by tobensg and then check your memory, one stick at a time to verify they are good.