I used to have 2 512DDR cards installed in the computer, today I bought a new 1GB card. So I tought that I could use the 3 of them and have 2GB BUT whenever I put any of those cards in the middle slot for RAM the computer doesnt start up and it beeps continuosly; Ive tried all combinations possible using the cards like putting the 1gb card in the last slot and a 512 card in the middle one, two 512 in the first two slots and the 1gb one in the last one, but it doesnt work in anyway if i place any card in the middle slot. Ive searched in the internet and some people say that it is a 64K RAM problem or something like that but they dont give a solution for the problem. Anyone that could help me with this problem please? Thanks in advance. PS: Ive switched around the cards and im currently using the computer with the 1gb card and one of the 512 cards and all of them work fine, the problem only happens if I place one of them in the slot on the middle.