i am current running 2x1gb corsair pc6400. I have 2x1gb Kingston pc6400 spare so i thought i would put them in my system to give me a total of 4gb. however when i turn it on i get beeep beeep beeep ??? So i took one of the kingston 1gb sticks out so i then had 2x1gb corsair and 1x1gb kingston and it booted up finee ??