I recently fitted a Kingston DDR2 1GB 800mhz module on my Intel D102GGC2 motherboard. The board has two slots for RAM & supports a maximum of 2GB. One slot was occupied by a Dynet DDR2 512MB 533mhz module. So I expected the total memory would be ~1.5GB.
However, only the Kingston module is recognized. The Dynet module is not recognized - neither by Windows, nor by the BIOS. The BIOS states that one slot has 1024MB RAM while there is nothing installed on the other slot. However, a 3rd party program, SIW [System Information for Windows], can see both slots occupied but states that the mobo only supports a maximum of 1GB [which is incorrect] & therefore puts the total RAM installed at ~1GB.
So far I've installed both modules individually one at a time, interchanged the slots in which they were fitted & also updated the BIOS to the latest version. After trying out all of the permutations as stated above, I've concluded that the hardware [both modules as well as both slots] is fine.