Why can't you register? Are you having some technical problem?
The reason that we don't put specific, detailed help on the puzzles in the forum is that people have asked us not to. It's too easy to accidentally bump into solutions that you didn't want to see, and it spoils the game for people. So, we handle giving solutions to puzzles via PM. It's actually very effective, and we're pretty quick at responding to PMs (unless we're asleep, of course)!
