Regarding the Beo4, I suspect bad contacts in the battery compartment or its wiring, or corrosion on the circuit board. Are there any signs of batteries having leaked in the past? It could also be just plain faulty, although that is quite rare.
In any case, I don't think it will be cost effective to have the dealer fix it - unless you're willing and able to tinker with it yourself, you might just get a new one at a popular auction site and flock the old one with the fault described. I believe it would still sell nicely and you wouldn't lose much in the end.
On issue 2, I can't really help but I certainly don't buy the explanation you were given.