Hi Bill
I just went through the same problem on my ES. (see link below)
My circuit is the same as Simon's above, but with kit parts.
After 2 days of testing I had a feeling that it was one pot.
I found the pot worked fine when testing it out of the circuit.
I replaced it and the guitar circuit worked. I then put the original "bad" pot back in just to confirm it was not my soldering. Did not work.
Somehow the pot seemed to be breaking down under load.
I think the odds of that happening are pretty slim in the first place, having two in a couple of months even slimmer. Perhaps they could have come from the same batch hihi.
Greg