I use Lightbox Plus Colorbox (LPC) and have done for a very long time. Works exceptionally well throughout the website. However the recent upgrade to MP 3.0.2 has caused MANY issues (search my user on this forum for a complete list of errors).
One error I noticed is that when I have LPC active, it doubles up on the lightbox links in the MP category pages. So if I click an image link or a Choose Options link it will try and open 2 lightboxes and will get stuck in a loop with neither opening.
If I disable LPC the MP category pages work perfectly. But disabling LPC is not an option as I use it elsewhere on the site.