Viewable images for users who are not logged in

I know this has to be a simple fix, but can someone help point me in the direction of setting up Wiki permissions so that people who are not logged in can see images in the Wiki? Right now, none of them are viewable unless logged in. All other text-based content is there.

Set the Forum Permissions for the Not Logged In group on the Wiki Images forum. Make sure Can Download Attachments and Can View Thumbnails are both set to Yes. This is how vBulletin determines that an image is visible.