Pop up images no longer working

SInce I upgraded to 1.5, my "larger image" links arent working properly.
When I click to see a larger image, the image is opened in a window that is much too small, plus the whole site header is included.
Please take a look if possible and let me know how I may fix.
http://gasolinecowboys.com/store/index.php?main_page=document_general_info&cPath=1&products_id=21
Thanks,
Rich

Re-install Lightbox . Just tested last version on 1.5 and is working very well .

I am having trouble installing Lightbox v1.6.
I have uploaded all the files but when I try to import the SQL patch I get this error. Can someone help me?
Thanks,
Rich V

#1146 - Table 'gasoline_zc1.configuration_group' doesn't exist

#1146 - Table 'gasoline_zc1.configuration_group' doesn't exist
Load your DB in phpmyadmin and look for the table prefix gasoline_zc1
Or see what preceeds configuration_group

Thanks, I see that each table is preceded with zen_ , i don't have a clue how to bypass this and successfully install the patch. Can you help?

Try installing the patch through the admin > tools > sql patch

It is designed to overcome/add the correct prefix