My card is auto detected in my Core.
I log onto webadmin, and delete it, at media directors.
If linuxmce asks again to auto add it, I say, no never, do not ask.
Then I go into computing -> mythtv-setup.
I delete all entries, also linuxmce-default.
I add the card, and make all my manual entries, safe and wait for mythTV to do all it's stuff.
Then I reboot and check if everything works.
This is the only thing that works for me because I have no clue what linuxmce-default is doing, and I cannot make head or tails out of the manuals, I just do not get it.