I think I got this fixed now, changed the "disabeled" field in the "Devices" table to "1" which prevents them from being started.
And then I reckoned there probably was a setting like that in the web-admin as well. Indeed, when you select the device from the drop-down box in the devices-tree, there is an option "disabled", which is now checked for these devices...
So now I'm just going to try and turn the "vlc" and "vdr" options (that got me in trouble in the first place) off again and then try and remove those devices manually in the web-admin devices-tree. That seems to me like it would be the easiest and cleanest way to fix.
That is pretty good news indeed nite_man, any luck so far?