Some of the OEM units are VIN specific. There is a microprocessor circuit in the head unit that requires a security code from the vehicle. A Ford dealer can reprogram it for a price.
I have seen posts where people have removed the security circuit from the HU. I don't have my finger on one right now.
There could also be harness changes between 08 and 09.
You should, however, be getting more than just eject cycle functions. If properly wired up the HU should light up with something like "RADIO LOCKED" in the display window.
There is both a constant power circuit to maintain programing in the HU and a ACC feed that powers the HU with the key on.
'07 GMC 2500 6.0