Anyone having problems with these? The wiring is pretty flimsy and the wires break right outside of the flexible cord protection coming out of the power supply. Buying new power supplies is expensive ($35 each). I, of course, want to always have two with me in case of failure, which is costing me $70. Anyone else having these problems with the px-2g? Suggestions on how to make them last longer? I've gone through two of them in the past 5 years.