Hi Mark, We aren't supposed to presuppose what a sparky will say or do. The textbook answer, as I said above, is that the outside disconnect is the main panel and the inside panel is a sub-panel. Given that, you have to separate the grounded conductors and equipment-grounding conductors on separate buses by adding an equipment-grounding bus and then install a bonding screw in the appropriate location on the exterior enclosure, exactly as Richard states above. That's the way you write it. The reality is that what will then most-probably happen is a sparky will come out, make some comment about "Idiotic friggin home inspectors don't know their a** from a hole in the ground," and will install the bonding screw in that hole at the strap between the two neutral buses at the top of the inner panel, replace the faulty breaker, close the panel up, and walk away. Because the two panels are joined by that metal hub and conduit, I don't think it will make a bit of difference to the electricity passing through there. If something happens, it will still do exactly what it is supposed to do in a perfect scenario, albeit in a not-so-perfect way. That is going to be the sparky's call and when he makes it you should simply shrug your shoulders and say, "He's the electrician, not me; it's his call." Just explain to the client that you are the family doctor and that the sparky is the brain surgeon; if the sparky chooses to make an unorthodox call it's on him, not you. Whatever you do, stay out of it from the point where the sparky gets involved. Don't dispute the sparky's work unless you want to become ensnared for practicing as an electrician without having an electricians license. Just document every conversation and archive every email related to the issue and make sure the client understands that you've washed your hands of it once the sparky touches it. ONE TEAM - ONE FIGHT!!! Mike