If I fill all four DIMM memory sockets would the following configuration be legal for dual channel operation or do all four memory boards have to be identical? Dimm A1 Dimm B1 Dimm A2 Dimm B2 512Meg 256Meg 512Meg 256Meg From the explanation in the manual it's clear that the memory in each channel DIMM A1/A2 and DIMM B1/B2 must be identical, but it's not clear to me if both channels have to be identical. Any input will be appreciated. moe