Hi all. I've bought a iBook from eBay for my mum and grabbed a copy of Leopard, but every time I try and install it I get the following message: "Install Failed - The installer could not validate the contents of the 'BaseSystem' package. Contact the software manufacturer for assistance." I know the disc itself is fine as I previously used it to install Leopard on my Macbook. I've also just bought a brand new 1Gb stick of memory from Crucial as I read in a few places that "this message is due to faulty RAM in 99.9% of cases". I'm obviously not very happy about this.. Its a white iBook 1.33Ghz 12". Model Number: A1133. Any help (before xmas) would be gratefully received!