OWA Exchange 2000 Logoff error

I’m using Exch2K sp2 on Exchange 2K sp2 with OWA. When I hit the Logoff icon in OWA I get an Http error 500 – Internal Server Error. I have tried this with several accounts from different locations and get the same thing. I am NOT using a Front End/Back End setup. I don’t have any problems logging on.