I plan to add another 1 stick of PC3200 512MB RAM in my existing configuration, which has actually 1 stick of PC3200 512 RAM. However, I don't know what brand it is and not sure what brand I will pick. Do both memory sticks have to be of the same brand? And secondly, if I just plug in the new RAM, will it automatically work in dual-channel or is there a certain setup you have to do?