WCF Web Services, IIS, Kerberos, and Delegation problems are maddening!

Sometimes you implement something exactly as you have in the past, but due to some unforeseen circumstance it doesn't work as you expect. We've seen issues like this when implementing WCF web services on IIS 6.

Some things you can check are:

- Have you setup the proper service principal names for the service account running the application pool?
- Is the service account setup to run the application pool that is running the web service trusted for delegation?