> (on the requisite 30A fuse BTW...#14 wire)
I see that in almost every panel or this sort.
> do you mean the PoCo's or the one I tested with?
Yours.
>With both the tub drain and the sink drain bonded, the problem seems to disappear.
What if you just bonded them to each other but not the panel?
The only other things that kind of fit your data are a 240 V fault where there is no net current flow on the "neutral" you created, or a fault from a source not supplied through the panel to which you bonded that now takes a different path to complete its circuit.
