Hi again,
I was poking around in the User Guide for this model (http://tda.panasonic-europe-service.com/docs/2z539782a3z3z24a27z656ez706466z22z7e45bdd319a84b9082c40ffee2f1dce64fa8ee81/…) and see a couple of pages that might shed some light on this:
Page 35 - Input Resolution
Page 44 - Aspect Ratio
Not sure if you've already taken a look or not.
