Migration assistant will not see drive

[subnet32]

Greetings to all gurus -

I am trying to migrate from my 10.4.10 G4 to my 10.5.2 iMac via firewire. My G4 has two drives: a main and a backup, both bootable. While Migration assistant will see and import users from the backup drive flawlessly, it will not see the main drive.

I have tried to migrate via the network, but no love since the migration assistant on the G4 does not have the 'migrate to' option.

Thanks for your time in addressing this issue.
James