Hello Klaus, thanks for your data.
The source is a 24" 2009 iMac 10.6.8
The target is a 27" 2011 iMac 10.8.2
As I've described, I followed the steps of document HT4413 until step 9 in wired network section (also tried wi-fi)
About firewire procedure I know I can start 10.6 holding T to act as a firewire disk but I cannot connect it with the host 10.8, I have a cable to connect an external disk to a computer and another one to start a chain, to connect firewire disks disks. Plugs and terminals are different so I cannot connect both computers.
Migration Assistant *****!
iMac 20" (mid 2007) 10.6.8 > iMac 27" (Late 2012) 10.8.2
Tried migrating from backup drive... stuck at one minute remaining FOREVER!.
Tried migrating through Ethernet cable... Computers cannot find each other.
Had to manually move things over ~ what a waste of my time. And having to give every folder permission status is a joke ~ I just ended giving the old hard drive complete permission status.
I remember the days when Apple made things that "Just Worked".