I just reinstalled 7.0 and can't login on the console. This is setup in VMWare (vSphere 4.0). I have tried every possible combination I can come up with for both 'root' and 'admin' passwords, including the '00000000' and MAC addresses like the appliance. Nothing. I was lucky enough that it did give show the DHCP IP that it picked during boot, so I was able to login to the UI and redo my configuration. However, I still can't login to the console of it.
Are you using the VM console or via SSH?
If you didn't go through the wizard at boot and answer the last question about root access via SSH, you will not be able to SSH into it at all.
What a drag. This was on the console. I don't recall seeing an option to go into a setup wizard after it booted. Luckily I just reinstalled it and it hasn't been running long, so I'll just redo it and try again.