I am about to receive a 20" iMac Mid 2009 (Education only) model that runs the Core 2 Duo 2.0Ghz and has 4Gb 1067MHz DDR3 RAM installed. I have read conflicting stories about RAM upgrades. EveryMac seems to say that when this model was initially released, there was an EFI limitation that restricted this particular model to 4Gb max RAM but that the restriction was lifted at a later date and 8Gb is possible. I have read conflicting information elsewhere and nothing concrete. I'd like to upgrade using 2x4Gb 1067Mhz Crucial memory DIMMs but I am reluctant to buy some try it out in case it doesn't work. I took a note of a serial number from a sample machine but I am not sure if it will be the actual machine I receive (there are 9 being auctioned off). If anyone can check for me using that serial, please let me know! It is: VM933MVH6MH Has anyone had any experience with this issue or could check for me? Thanks in advance, M.