I think they're might be a jQuery conflict with your plugin and my website, for example the gallery at http://www.wornmagazine.com/2010/06/activation-portraits-polaroids/.
I was previously using jQuery Lightbox For Native Galleries and it worked great. But then one day it stopped working and now the thumbnails just link to images. After some discussion nobody could figure it out, so I deactivated and deleted the plugin and installed yours. Still, I'm having the same problem.
I honestly don't know if a plugin I installed caused it to malfunction, I rarely use the galleries so I'm not sure when colorbox stopped working.
Any ideas? Thanks for your help!