Did you install the demo data and then started your work from there?
If so there will be some restrictions for the anonymous user in place, it will only anonymous users to view certain classes. You should check out role/list to see what policies are set on the different roles.
I knew there was a catch. I did not install demo-data, but oddly enough, the "Anonymous" user had a restriction to only view content of types 1 and 7...
I have never touched those settings, so I don't know how type 7 got in the, but not any of the others... I'm suspecting some other admin at the site has been playing with the setting, though...
The restrictions were from the demo data, they were required for the demo templates to work properly. It's generally a good idea to reinstall with kernel clean when you want to develop for the site.
