Like I said, the forums were acting strange, I think I was the last person to post in the thread, and it had double posted for some reason, so on deleting my second post it php errorred and said to me that I could only delete post's created by me(?!?! - I had quite definately only clicked on the little 'x' next to my second post).
Do you think, that delete post request/error could have been messed up on its way across the internet and somehow got admin priviages and corrupted that topic into non existance?