If I view a image in a gallery and there are tags associated with the image, after clicking on tag I get a list of images for that tag. If I then select one on of images it gives me the following error:
Fatal error: Call to a member function getTitle() on a non-object in /home/ahmobima/public_html/photomarc.co.za/zp-core/template-functions.php on line 912

Please try a standard theme. If it works there this is a theme issue the theme's author gjr surely will respond to soon.