I have contacted Apple Support
... and they and I went through a number of things... (Many of which I'd already tried)...
Trying to boot off the DVD, "C" key, 'option' key boot, single user boot... NADA, ZIP, etc., etc...
Put the tiger DVD in and it recognized it right off, SSOOOO don't think it is the DVD drive. The drive does A LOT of searching when I try to use the Leopard disc... I've got as far as it bring up the 'restart your computer to begin the install'.... but then when it self-boots... it can't recognize the DVD and spits it out....
Apple is sending me another DVD, via 'herd of turtles' shipping..
Bad news is that I put the DVD in my wife's G4 Macbook.... and it recognized it right off...
so don't know what that means... maybe her DVD drive is 'more forgiving than mine??!?!?
Bob K. rnkiii