Did install from ubuntu-13.04-desktop-amd64+mac.iso on Macmini6,1 and built-in ethernet did fail, symptoms matched as above in this ticket.
Did add USB ethernet, enable proposed, install new kernel -20, remove USB ethernet, reboot, and the built-in ethernet was enabled.
Did several scp of large files to confirm.
Did install from ubuntu- 13.04-desktop- amd64+mac. iso on Macmini6,1 and built-in ethernet did fail, symptoms matched as above in this ticket.
Did add USB ethernet, enable proposed, install new kernel -20, remove USB ethernet, reboot, and the built-in ethernet was enabled.
Did several scp of large files to confirm.