NHibernate and Oracle 9i

Spent 1.5 hours troubleshooting the following error when using NHibernate 2.1:

"NHibernate.HibernateException: Could not instantiate dialect class NHibernate.Dialect.Oracle9Dialect ---> System.TypeLoadException: Could not load type NHibernate.Dialect.Oracle9Dialect. Possible cause: no assembly name specified."

I was looking at outdated documentation. The correct dialect is "NHibernate.Dialect.Oracle9iDialect" (emphasis mine). "NHibernate.Dialect.Oracle10gDialect" is also valid.