you could try unplug the tv over night, or for 3 or 4 hours to power it down, and then try it, just make sure that there is no dirth ect in the headset port at the back of the tv, that would turn the headset to ON, try pluging the headset in, and see if they work, this will also unblock any dirth ect in there. but i would try powering it down, and see if it will clear this setting..
m, October 2011