I just purchased a new iMac 24" from my University's computer store. I had them install extra memory, since their price was a lot lower than Apple's. But I just noticed that they installed 667 mhz memory, rather than 800 mhz memory. The machine is blazing fast, so I'm not worried about speed. But should I be worried that the wrong kind of memory might affect the system in other ways? Any advice would be much appreciated!