FYI, I attempted to re-generate the server and client keys using md5 instead of the sha1 hash and the problem persisted so it looks like it's safe to use whichever.
Just for the heck of it I went to usr's support web site and decided to load the latest drivers for the client computer. After doing so, everything worked as expected. The only other things I did at the same time that might also have fixed this was to make sure that reverse and forward dns lookups worked correctly, and made sure that the usr 8054 wireless router had its' time synchronized with the server. I hope this helps others! - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
