I see what you're saying.
The motherboard's manual does not place any restrictions on the possible combinations of CPU and memory. It does not even say that DDR and DDR II cannot be used simultaneously. It is actually possible to do, it all depends on the ability and versatility of the northbridge's memory controller. Looks like a nice little transitional board.
Given the nature of the board (a multiple technologies bridge), I doubt it offers the maximum performance possible. On the other hand, if the performance loss isn't too bad, say, no more than 3 to 6%, it is still a nice alternative to shelling out possibly a couple hundred dollars for new memory.