Hi there, I have this motherboard and want to upgrade memory from 512MB to 1GB. Right now I'm using two memory banks (I have 2 x 256MB modules) and my question is: Can I just buy a new 512MB module and insert it in the third memory slot? Or should I buy a whole 1GB in either 1GB or 2 x 512MB? I'm not sure if the motherboard can use one or three slots only. Thanks in advance, -Benton