A recent firmware upgrade from Samsung has done more harm than good by blocking them from playing Universal and Warner Bros. movies.
After updating to v2.09 for its 2009 BD-Px6000 line of players, it would lock up after displaying the title image but, just for Universal and WB movies.
Samsung has graciously posted the previous firmware (v2.07) on its support site for users to downgrade to, if they are experiencing problems.