For some reason when I upgraded to R2 spotlight no longer works from lightbox, and the buttons for it are missing entirely.
Not sure about how to get it back working from Lightbox (I actually prefer it to do it manualy) but all the buttons are in the Texture Palette. And the Edit Spotlight button is in the transform palette.
Also check this thread:
http://www.zbrushcentral.com/showthread.php?161310-What-happened-to-spotlight-in-R2-Answered!