First as the above does not match the previous thread I will be branching it into a new thread.
When a customer has a problem with this product, be it rebooting, dropping, the usual suspects I always suspect the environment right off the back and I don't get proven wrong (at least not that I have ever found out). Please start out by asking customers to take the equipment to a new environment, for example taking it home with them for an evening. This has always in my experience proven to either make the problem better (this expected outcome) or made it worse (it still happens occasionally). Once we have confirmed a change in environment is directly the cause of the product being more or less stable we know the problem is interference, as that is all that has changed.