For the sheer hell of it disconnect the battery for a reset. I know you have already done this but maybe something is out of wack here.
Check the roller switches for the interior lights. Maybe they have gone bad , got wet or just failed. I would take it in as getting stuck due to a drained battery would suck.
I don't know what replacement switches would cost but it might be worth buying new ones to see if that is the issue if you don't want to pay the dealer to check them if your out of warranty.