Hi I have a late 2006, 20" iMac with 1 GB RAM running Tiger. I want to upgrade the RAM. The Apple support website says the maximum I can install is 2 GB SO-DIMM in each memory slot, however the iMac will only use 3GB total memory. My question is, if I upgraded to Leopard/Snow Leopard would the computer then be able to use the full 4GB? Thanks in advance for any replies, help is much appreciated.