In an earlier post I asked about upgrading my first generation G5 with a 1.8 Ghz single core processor from Tiger to Leopard. I was told that because my processor is not intel that I can not go beyond Leopard to Snow Leopard. However I have noticed that there seem to be different versions of Leopard and I would appreciate it if some one could tell me which version is needed for my specific IMac. I was also told that I should upgrade my Ram, which now stands at 768 MB, am I better off to just pull the 256 and replace with another 512 or go with a 1 Gig in addition to the 512? 