Date Picker Not Appearing on Pro Sites Coupon Screen (possible bug)

I don't know if this is a bug or a plugin conflict, but the date picker in the "start" and "end" date fields for Pro Sites plugin is not working properly for me (see screenshot).

I am running WP 3.5 plus a bunch of WPMUDEV plugins. I am running a couple of non-WPMUDEV plugins but nothing fancy.