I don't think it's the canola peoples fault, just a bad DEB file on the maemo server...

jack, looks like you already have avahi installed? Try installing canola again(after removing it completely) and see if it works. If not, try --replace instead of --install for avahi and then after it is removed do --install again

If that doesn't work, google for the DEB files to the dependencies it mentions. You can look on the oakcourt repo(sitory) too, it's probably there if avahi needs it,