I just picked up my new iMac at the Apple Store in NH last night. I got the 800MHz version with the Superdrive. I want to add a 512MB chip to the "user's slot" and these are the prices and specs I have received: from www.macsolutions.com 512MB CL=2 for $129.00 (1GB kit for $243.00) from www.crucial.com 512MB CL=3 for $235.79 what is the CL=? does this matter? I remember reading on this site, not too long ago, that people who bought some memory found it useless when they upgraded their firmware. Macsolutions "guarantees" their memory? Any advice? Thanks.