Panasonic won't do anything.
I was watching a bit of TCM the other day and at the end of the movie they showed a preview of Annie Hall. The way they show their previews now is they have a light colored rectangle that runs across the bottom of the screen and the name of the film (and maybe something else) in bright white letters and the trailer is displayed above that. Well I fast-forwarded through that so it couldn't have been on the screen for very long. But next thing I watched there was "Annie Hall" amongst the IR on the bottom of my screen.
If it's not getting any worse, it certainly isn't getting any better. ("Annie Hall" has since gone away, but there's always the next thing to get it going again.)
Anyway, try Disney's WoW pixel flipper. Not sure it quite got it all for me last time, but it does seem to help.
Also try turning down your contrast setting.