I just installed and got this working over the weekend. I agree that it takes trial and error - also, not sure if this is applicable or not but it seemed like the first time it took a while to get the connection established. I think I was too impatient -- got distracted for 5-10 minutes and found that it was working! So try 1,2,5,6 in the C4 driver first, reboot the security panel and wait. Repeat.
It seems to me that in your case, the AUI # is incorrect (either in the panel or in the C4 config), if you are getting all of the other right messages. I also recommend ensuring the serial connection is accurate by connecting to a computer and verifying you actually see the data (or have your dealer unbind the serial port and use a terminal window to run minicom against the port [/dev/ttyUSB1 in my case]) to ensure traffic is flowing properly.