Has anyone had any problems with HK 335 or 340 Receivers going into permanent "Protect" mode which effectively kills the receiver. My HK 335 had some sort of issue after little over a year and the factory replacement (a 340) did the same thing after about a month. I have not had any electrical issues in the house and even have added a whole house surge protector recently. HK has been great to deal with, but I am baffled as to why I am having this issue - is it a HW problem or environmental? Any thoughts?