I am not doubting that Apple only accepts the highest
quality RAM - but 1 in 1000 is a little crazy! I am just doubting
the "genius" that said that!
The genius said it but actually I have found some other mistaken comments by geniuses. For example, they told me that the Radeon 9600 graphics board that comes with G5's would work in G4's since they are both PCI boards... Wrong. After I bought one on Ebay I found it would not fit because of an extra tab space. They also told me to go home and test my G4 with the hardware test CD that came with it, later it turned out that my model never had a hardware test CD. Etc. They're just human and they have been trained in a relatively quick time period. I don't fault them for that.
Its possible that Apple has an arrangement where they test then return rejected memory. I just checked the prices now. Apple is selling a 2 GB kit for the G5 for $800....compare to $350 I paid for the Geil and $280 I paid for other brand. Thats expensive! The genius told me she has sold G5's to customers who literally paid more for the RAM than the CPU.