Lightbox Plus 1.6.3 has been released to address issues with jQuery conflicts especially with the Featured Content plugin.  Here are the latest changes.

1.6.3

• Eliminated conflict with Featured Content plug-in
  • Removed jQuery.noConflict() due to poor implementation on my part.
  • Kept $lbp jQuery variable.
• jQuery conflicts should all be resolved – hopefully.
• Minor modification to wp_enqueue_script function cal to include colorbox version.
• Now works with WordPress Mu if rel=lightbox[] is added manually.
  • Working on solving auto lightboxing issues with WordPress Mu

You can get it from WordPress.org or 23systems download Lightbox Plus 2.4.6 directly.

For support please see the Lightbox Plus message board.