Hyperic, how to change HQ Server IP for an Agent

I have been torturing myself for ages about this simple question...

just run
hq-agent.sh setup

but at the end of the process I get

"Error updating agent: Unable to invoke 'updateAgent': Permission denied"

When I do this, it works:

Would you like to re-setup the auth tokens [default=no]: yes

Would you like to re-setup the auth tokens [default=no]: yes
- Received temporary auth token from agent
- Registering agent with HQ
- HQ gave us the following agent token
1334082450388-1632010252278915721-1721183443318423049
- Informing agent of new HQ server
- Validating
- Successfully setup agent