When using Enterprise Serviced components with the Server activation option the NHibernate SessionFactory is always null. It works fine when used with the Library activation option. Any idea what is the problem?

One idea that comes to my mind is that the SessionFactory cannot find the config file. When you are in Library mode the config file get it info from the application that invokes de ServiceComponent. When you moved to Server Activation the component uses its own configuration.

Bare in mind that unfortunately for ServicedComponent prior to Windows XP SP2 every config you want to be read will be taken out of the machine.config.