dovecot - Nov 2005 - Error: auth(default): Unknown userdb type 'mysql'

Hi there, I have configured dovecot with mysql but when I restart
(Redhat enterprise 4) the following error appears:


dovecot: Nov 01 18:47:08 Info: Dovecot v1.0-stable starting up
dovecot: Nov 01 18:47:09 Error: Auth process died too early - shutting down
dovecot: Nov 01 18:47:09 Error: auth(default): Unknown userdb type
'mysql'
dovecot: Nov 01 18:47:09 Error: child 30738 (auth) returned error 89

I have all RPMs for mysql installed, as well as mysql-devel.

how can I verify that mysql support was correctly compiled in?
sugestions?

Thanks in advance.