Thanks for taking the time to post the excellent DIY for iPod install.
I had mine installed by the dealer last week. The tech said it took him about 4 hours, but said it was his first one, he was doing some experimenting, and felt that it will go much faster on the future installs. He made a point of saying he learned it was important to flash to the latest 'I Stage' (don't know for sure what that means) prior to connecting the iPod interface to the network. Could it be that not flashing prior to your install is the problem getting the system to recognize the adapter? Hopefully you won't have to go back and disconnect before flashing - what a pain?
My car's install was completed with the flash and coding process, but not a Progman update. The SA said the software portion of the install only took about 30 minutes. I was quoted and charged 1.5 hours labor for the install.
Thanks again for the writeup - hope you get it working soon.