Apple Tv Vs Panasonic Viera

I've buyed my ATV one year a go, and I've tried it on my Panasonic Viera Tv, everything went good.

Then I've moved the ATV to another Tv where I had to change the resolution.

Now I came back to Panasonic, and doesn't connect any more... I've tried all 3 Hdmi ports, I've changed all resolutions, tryng on Philips small hd tv (always ok).

Nothing... seems like no pair any more.

Maybe new update doesn't reconize it any more?

I'm Stuck !!

Any help ?

Thanks