@csskevin:
I have to replace the first code snippet you posted with the second one, right? I downloaded the wp-lightbox-2.js from my server, edited it and did so. I loaded it up again, but nothing changed: The lightbox still isn’t working.
I’m using the latest stable WP version and version 2.28.9.2.1 of the plugin.
Do you have an idea what could have gone wrong?