JS bug

After I installed this plugin my page breaks (js error on a theme file), which then makes another plugin (lightbox) stop working.

http://www.bonitavintagehighteas.com.au/gallery/birthdays/event-001/
The second image should open in a lightbox, but because of the error caused by the plugin (if a deactivate the plugin everything works).

Could you help out? Could this gallery function have a lightbox possibility?

thank you

http://wordpress.org/extend/plugins/rps-image-gallery/