Have you ever run across an "impossible" puzzle?

I have Clubhouse Games ("42 All-Time Clics" in the UK) for the Nintendo DS. One of the games is called "Escape". It consists of about 5 or 6 different shaped blocks that you slide around a rectangle. Some are small squares, some are like a double square, some are zig-zaged. There is one master square that must exit the door to win. It is blocked by the other pieces that must be shifted around to allow it through. There are 20 puzzles and I have solved the first 18. I am beginning to believe that the last two are impossible. There is no solution at any web site, just other people who have the same problem. A few people claim to have solved it but have no solution or proof. I am going crazy. What should I do?