Strange Screen When Booting From Cd


When I insert my tiger-dvd, my apple imac G4 starts freeking around...
The screen gets gray and they are flying pixels everywere.First I tought it had something to do with the hardware but when I insert Panther there is no problem... I can install Panther with no problem.

I've format the entire disk and i've reset the POST-controle or whatever it calls and still I can't get into the setup of mac osx 10.4....

Does any one knows what the problem is here??
I would also like to profite of the benefits of tiger :)

thanks for the reactions