Re: WTH is this: please insert the original disc instead of a backup(1000)?
my normal edition disc clicks in my drive too. Freaked me out too. Clicked a whole boatload of times, until it finally let me hit autorun, and I'm installing it as we speak. I have a cheap, uh, Lite-on?, lightscribe dvd rw dual layer SATA drive, just bought it a few months ago though. First disc I ever had this happen.
I hope it doesn't keep happening everytime i start up my computer or pop this disc back in.