The avahi 'thing' is already solved at the first post of this thread.

It's a maemo repository error not Canola app error, however i'm ashamed that the canola team hasn't posted something about this issue. Wouldn't hapen like that if this was open source I bet :P

the username/password popup can probably be set in a config file in the /home/user/canola directory, however you need to know where that is and I have yet to care to look.