Has anyone who has this model experienced the screen being loose at the bottom. The top and both sides are fixed to the frame but the bottom of the screen is not. I asked Panasonic about this and they said that is how it should be so that air can circulate and keep the tv cool. I have checked other Panasonic led tv screens on other models in the shops and they are fixed to the frame on all four sides. Unfortunately I can't find my particular model in my local shops so can't do a like for like comparison. If anyone has had this problem I would appreciate hearing from you.