Update, on another system I've been working on, XP-8, K4, T2CZ and Escient FP-1 has been having various issues. Arrived on site this morning (clients are away on holidays for a week), to find power Off to part of the house, including AV gear, and of course, refridgerator and freezer.

Let the clients know the 'good news' regarding the freezer, then found that the XP-8 and K4 to be 'acting up' even more than normal.

Put in a call to Greg at RTI Controls and he suggested, as I'm using IP Control, to do away with the control cable between the XP-8 and K4 and to power the K4 using the 16 volt power supply instead of powering it via the control cable via the XP-8 (12 volts).

Wow, what a difference, when I return to the job I mentioned in post 5 I'll be checking to see if this same solution helps.