Hi. I'm planning on upgrading the RAM in my late 2006 20" iMac (white) model prior to my upgrade to Snow Leopard later this month. My current configuration is 2GB RAM - I think 1GB in each slot; this was how I purchased it from the Apple website. According to Crucial, the max RAM that my iMac can take is 3GB and an upgrade of one of the slots to 2GB is recommended. My question is, is it OK to have different RAM configurations (i.e. 1 2GB chip and 1 1GB chip) in the same computer. I'm always giving conflicting advice about this... Crucial seems to think it's fine (there's a section entitled 'Do I have to install matching pairs?') and obviously Apple must think so given the 3GB max, but I have a friend who is telling me the opposite. Any advice would be appreciated.