About to take the plunge and dump the PC for a G5 iMac, but in doing my research I have come across conflicting info with regard to upgrading the RAM. I have read some posts where they say it is ok to have mismatched RAM in the two slots, and others where they say it's just fine. The installed RAM is only 256, and I was going to buy a 1GB stick. Can I leave the original 256 in there, or am I better off just using one slot with the 1GB, and then buy a matching one when I can afford it? Thanks in advance for your help.