This is related to this post http://www.gravityhelp.com/forums/topic/bulk-addpredefined-choices-not-working
I found that another plugin, AdRotate , conflicts with the thickbox on Bulk/Add Predefined Choices (opaque overlay appears, but box does not popup). This is a widely used plugin.
I'm thinking that this comment by Cristian Antohe is starting to make sense:
Another plugin that enqeues ThickBox is WPML. Maybe you can contact them about it as well.
I know this isn't GF fault, but you could always do a:
on GF pages and register your own gfthickbox afterward. Might save people some time :)
I can't believe that I am the only person seeing this problem, given the number of plugins out there?