After looking at at some things, I think that XMLTV may be writing into the database some weird values or something that get retained. I noticed, I could get XMLTV to populate values but the import channels from tvguide.xml option returned an error which got me thinking. After deleting all my channels and deleting the tvguide.xml and tv database, running the plugin, saving the channel list from the plugin, then autotuning, it is working normally again.
Not surprising as this plugin and XMLTV use different logic and means for mapping/populating the database.
I wish there was a way to trigger the plugin running manually like there is with XMLTV.
There is a option to run the update the next time MP starts.
HTH,
patrick