@tournedos, I have very limited knowledge in electronics (high school only and thats a while ago :P ) but I read somewhere that the piezo was rahter sensitvie to heat.
Last summer I had my BL7000 in charger since it was missbehaving outside charger (turning on and off all the time til battery was drained). Something happend a hot day and my original batterypack got very heated, it was almost too hot to hold your hand against faceplate. When I pulled out the batterypack it was also very hot. After I let the BL7000 cool down and replaced the batterypack with a new one the faceplate is totaly dead, with no reaction on other touch or a more brute tap :(. Suspected that i had freid the piezo then.
@Leslie, I will take up that offer, but lets first see how your "blue-cap-adventure" goes :). Btw in swedish your saying is "En bild säger mer än tusen ord" we use it also.
Cheers
Jesper