Problem with Target Disk Mode iMac -> MacBook

[edalzell]

I have an old iMac (Summer 2001) with 10.3.9 and a MacBook with 10.4.9 on it.

I want to mount the MB HD on the iMac, so I start the MB in target disk mode. When the iMac attempts to recognize it, I get an error along the lines of, "Disk not recognizable, Initialize, Ignore or Eject".

I can put the iMac into target disk mode and have the MacBook mount it properly, just not the other way round.

Any ideas?