Hi everyone, I want to upgrade my friend's iMac RAM. Her model is Early 2006 (I think one of the first intel machines). She has 512MB DDR2 670Mhz RAM. I was wondering if: - I have to install equal size RAM on both slots - I can install ram of different speeds (since the old one is 670Mhz, and perhaps the new one is 800Mhz). Is that okay? If this helps, she's running on Tiger.