Sorry for the second post. I clicked ok and waited around 3-4 minutes and nothing happened, clicked OK again and 2 posts. Sorry

Ewanm

It happens because the script define wrong size of unloaded image or image placeholder.

I fix the problem by this way:
1. Go to /CMSScripts/Lightbox.
2. Open "lightboxLoadex.js" with any editor
3. Find
if ((windowWidth < 0 || windowHeight < 0))
at lines 23, 54, 107 (in my file)
4. Change it to
if ((windowWidth < 50 || windowHeight < 50))
5. Save and reload. May be you should clear the browser cache

Please, note! It will not work if you show images less then 50 pixels at any size.