@hwittenb: Using the full number tells them that it's a local number (for some reason.. which I thought was strange), and that they have to try without the '1'.
Their phone company btw is embarq (or whatever it's called nowadays).. so I assume their tables are pretty up-to-date. (assuming though.. never sure!)
It sounds like it is a valid number and the local phone company's routing tables are not correct. I would think the subscriber should complain to the trouble number of their local phone company.