I think we have found the problem and it does have to do with permissions, but not in the way I thought <g>. The client has installed the application on a workstation that accesses the beta environment, not production. The user in question doesn't have adequate rights in that environment. The app needs to be run in production. I guess that should be one of the tenets of support when you can't actually see the environment for yourself: ask the really dumb questions first.

Thanks for your help.