OC'ing ram isn't always the smartest idea.. I mean, some motherboards won't take it too well, and if you manage to get two different speeds on two sticks, you're in trouble.. But yeah, I guess your idea works here.
This brings out a fact that many computer need to identify what type of ram they have in BIOS. I seriously think this is a software flaw that the type of DRAM you have is not shown. However, i'll download this program and check it out.
It's important to know what type of RAM you have. Many dealers sell systems with 400 Mhz bus mobo and install 266 Mhz RAM. If you are going to buy a system, these are the two most important parts; mobo bus speed and RAM speed. Don't buy if the RAM are slower than the bus speed, and check if the mobo have OC capabilities.
Software wise, it is always more important to initially make sure to know what hardware you have.