FATAL Error after changing Asterisk Manager Password

I have changed the asterisk manager password in both amportal.conf and manager.conf but I now have a FATAL asterisk error. Can anyone advise what I need to do to resolve?

Connecting to Asterisk manager interface…Wed, 01 Dec 2010 16:45:46 +0000 - Failed to login.FAILED[FATAL] Asterisk Manager Connection Failure Failed to connect to the Asterisk manager through port: 5038

A re-boot of the server fixed this.