Problems mounting Imac in target disk mode on retina laptop with a solid state drive as host

I'm trying to use an Imac in target disk mode to copy files from it to a new retina display laptop with a solid state drive, but the target drive will not mount even tho it does start in target disk mode. I have all the proper firewire connection. The Imac will not respond for more than a few minutes before crashing when started from its own system. I would like to salvage a few files from it before I perform a clean install of the system.

Anyone has any idea why it wont mount in Target mode onto the retina laptop? Help!

Thanks in advance. :-)