Inline fan wiring

I just saw the post from Vodkapundit about the 3-way switch problem. I Have exactly the same problem. I am certain that I connected the wires exactly as they were because I drew diagrams of the connections prior to removing and replacing the switch boxes (not the switches themselves). I was replacing the old metal boxes with new plastic ones while we are in the midst of knocking out walls. The only difference I am aware of is that one switch is new 12 gauge wire with ground and the other switch is the old romex wire with no ground. The ground wire was not originally connected to the switch, but I connected it. Could that be the problem? Thanks.

Has the quality of the QO line gone down. A lot of people recommended them in posts. I got one of the 6 breaker subpanel and went to install it tonight and found it cheap feeling.. Along with the flimsy little bolt on ground bar. The final straw for me was the knockouts werent properly done, and I cant get the conduit in without filing the hell out of it. Granted I dont know much about them, but has the quality of Square D gone down.. Would anyone else recommend a subpanel. Thanks, Tim