I have had quite a few of those Audio Note copper PIO's short out in my gear too. Peter Q over at AN has admitted that there are some issues with those caps. The film that separates the dielectric is the problem. It breaks down eventually causing the cap to short out. Peter has redesigned the copper PIO's using a mylar divider that is supposed to be good for a long long time. Peter has agreed to take back any shorted out copper PIO's and exchange them for the new mylar coppers free of charge no questions asked. I know you have coppers in that kit 2, because I put them in myself. The coppers really are what sounds best in that amp, I would take Peter up on his offer to exchange the shorted ones. The new ones will have white lettering on them. the old ones had black. Also I would check all the coupling caps and cathode bypass caps in there. You should get no more than a few volts across any of the signal caps. If you're getting high readings like in the 80+ volt range, then they are getting ready to go. Replace any that you find like that immediately.

Mark