Hmm. I am probably wrong, but my only thought is that the Keg could be running an older firmware version.
On your computer, with the DMS connected, go to Tools-Preferences-DMS-Firmware/Plugins. It should show you which version of the firmware is installed on the DMS. The last Kenwood firmware version is 13.01. If the DMS is running an older version (any number less than 13.01), it's very likely that the Keg is also running the older version, and needs to be updated.
In that case, download VorTechS' Phathack DMS Tools (in this thread:
http://forum.phathack.com/index.php/topic,1641.0.html). Use the DMS Tools Mode to load the 13.01 firmware, being sure to check "Install Non-hacked firmware" and "Reflash box with firmware."
To flash the box with the firmware, take the DMS out to your car and put it in the Keg. Turn on the radio so that the Keg powers on. The red light should be on and the green light should be blinking, indicating that the update has started. You can turn off the radio and leave it for 10 minutes or so. When all the lights are off, the update has completed.
When you start up again, see what happens. Most likely you will have to reset the head unit again, and you might have to disconnect and reconnect the Keg.
Of course, if the firmware is already up to date, I am afraid I am out of ideas.