Those 3 channels are all on the same transponder which is on 9 Network: 191.625MHz for Adelaide. I have seen a similar issue before where channels that are 125 KHz off the centre frequency will not be detected during a scan.
Could you try this to see if it fixes the issue:-
go to C:\Documents and Settings\All Users\Application Data\Team MediaPortal\MediaPortal TV Server\TuningParameters\dvbt and edit the file "Australia.SA - Adelaide.xml" to change the value 191500 to 191625 and then try scanning again for Adelaide.
This time it should find all the Network Nine channels - but let me know if this suggestion fails ....
Yes, but it is just a "work-around" rather than a fix.And the fix for Brisbane or other states along the same lines?