I put on a R4 copy of Shrek last night. It hit chapter 5 and locked up my DVD player. I cleaned the disc, and it still wouldn't play. So I put it on my other DVD player and it did the same. The disc is completely unmarked. Now this was a replacement disc from DVD Crave which did exactly the same, so I'm thinking it could be a problem with the batch? Has anyone else had a problem? The disc says dual region coded 2/4.