A bit of a strange one, I have a vocab called "Creative Commons Licenses".
I have a content type called "Painting" that includes a term reference field for the Creative Commons Licenses vocabulary above.
In Views, I create a simple content view block that lists the title of the node. This block displays fine, until I add a relationship to the taxonomy term.
When a relationship to a taxonomy term is added, the view is not displayed for anyone but user 1.
I'm a bit perplexed here, there are no errors and no modules doing anything interesting with permissions.
Any help would be appreciated.
The following module was the culprit: Private Taxonomy Terms. Disabling this module resolved the issue.