thanks for answering. DVDs run just fine. Meanwhile I found that it does the same thing with the external firewire DVD drive. well. not a firmware issue, it seems.
I can install, I just can't keep the users.
I have two partitions on my hard drive with a system each in case I need to use tiger. maybe the easy-installer doesn't like that, or doesnt like something else, who knows. I'll go look in the leopard install section but will check back here in case you have something to say.