Originally posted by c0lefalk
I'm gonna make 'em short, since I can't get any long ones to work.
[fen]rnbq3N/ppppkQpp/3b1n2/8/4P3/8/PPPP1PPP/RNB1KB1R b KQ - 0 7[/fen]
The problem is that you are doing nothing to force any kind of sequence. Shortening the length of your PG's will not fix this.
In this one, it obviously does not matter whether White starts 1.e4 2.Qh5, or 1.Nf3 e5 2.Nxe5. You can't just play out a bunch of moves, capture the diagram, and then call it a Proof Game. You will be cooked every single time.
What you ought to do is study other Proof Games that ARE sound. Try to cook them. Try deliberately moving pieces out of order and see why it doesn't work. Then you will start to understand some of the sequencing tricks composers use to force
their intended solution to happen.