You should make sure that you use the 'Deactivate Source' option to turn off your AutoDJ rather than restarting the server.
Then in your control panel configuration make sure you have this set as:
'Disconnect listeners if source disconnects: No'
Finally you will need to make sure that you are streaming at exactly the same bitrate/samplerate/channels as your AutoDJ for a smooth changeover and without disconnecting listeners.
We hope this helps. 8)