Help, I bought a new TV just before Xmas - a Panasonic Viera TX-L55ET60B. The picture is great but now theres a sound lag between my Home Cinema system and the picture on screen. So, if I'm trying to watch a DVD its like watching an old Kung Fu film that has been badly dubbed. I've bought new audio-visual cables but theres no improvement. I get the same problem if I try to watch the TV via Sky with the sound channeled through the Home Cinema system.Theres a delay. If I keep the TV sound on as well its like there is an echo. My Home Cinema system is a SonyDAV-S300. I've had it for about 10 years and the sound quality is still great but at the moment I can't use it! I've tried everything I can think of. Have I plugged the right cables into the right ports? Are the TV and system just incompatible? Would appreciate any help. I've been in touch with Panasonic.They say its the Home Cinema system and there are no settings on the TV to rectify it. Sony said it was my audio/video connection - which I've now replaced.