Actually it works out-of-the-box with any permission (subscriber/contributor/author/admin/). I haven't found any single report like this with the plugin. Can you try in the default twentytwelve theme disabling all the plugins?
Actually it doesn't require any specific user roles. That way with WPUF, every user role (even guests) can upload photos, where in standard WordPress Subscriber and Contributors can't upload any photos. So the problem with you doesn't really makes sense.