Taxonomy image fields not working with private file system

I've seen this issue before, but only a long time ago and/or with Drupal 8.0 so I figured I had to refresh the issue?

I have Drupal 7.22 with a private file directory above my root. I can create Image fields with nodes and ImageCache etc works fine. However, adding an Image field to Taxonomy doesn't seem to work. I get the initial file upload to show as a thumbnail and appear in the TMP directory, then I even get the original file and the variants created by ImageCache to show up in the private files directory. But on any subsequent page load I get the "/system/" paths and permission denied on the image requests. And again, ImageCache requests are working fine in the nodes.

Any help or pointers appreciated!