In the current release of the The Mambo/Joomla PonyGallery component, support for MamboJoe's Community Builder component is hardwired into the picture detail page. The Author name is a link to the Community Builder component. If you don't have that component installed, here is how you can remove the link.
You need to edit the PonyGallery script sub_viewdetails.php. This script is in the components/mod_ponygallery directory.