I had this happen to me and it was a fucking nightmare to say the least....spend 2 days on the phone constantly to halifax chasing a vanished 3k cheque.

Absolutely shocking that can actually loose your money!

You must have a receipt for paying it in or some sort of infoirmation from teh guy who's cheque it is (get him to contact bank and find out where his funds went to).

Good luck and it woint be easy.....worst thing is the guy I was selling to thought I was ripping him off as his money had gone from his account :S

Cheers
Dan