Migration assistant between old and new iMac via Ethernet cabel does not work

I have a problem transfering files form my old iMac (5,1 or Mac OS X 10.4.11) to my new iMac (Mac OS X 10.6.8) using Migration Assistant.

I connect a ethernet cabel between the computers and follow instructions on the screen.

However after submitting the password the two computer keep searching for something (old computer states; "Searching for computers...") (new computer states; "searching for other compuers.." or "preparing files").

Can someone help with a solution to this problem.

Cheers,

Jacob