[grails + xfire] How to handle errors in SOAP services?

Question

Hi all, I'm implementing a web service on the xfire plugin.

I was wondering how I'm supposed to handle the errors. I tried with this setup but the error is not returned to the SOAP client:

GaSession[] myMethod( String userId ) throws MyException{
    GaUser user = GaUser.findByUserId( userId )
    if (!user) throw new MyException("user ${userId} does not exist")

            // do stuff and return valid results
}

Is there a standard way to handle errors and return them to the client in a clear way?

My log is full of messages like:

2010-06-13 18:20:40,926 [Thread-289] DEBUG aegis.XMLClassMetaInfoManager  - Mapping file : /com/mycompany/MyClass.aegis.xml not found.

Is there a way to fix this?

Cheers!