There is a bug in the tradeblock where auctions can't be cancelled when they have expired. It means items are stuck there. When i tried cancelling it came up with this message:

'WARNING  Sorry, but this auction has finished! You can no longer cancel it. '

Is there anything i can do?

I have the same. My K'torian p-axe [netherwold] is locked "Locked for Trade" 

This is still happening? Perhaps it was fixed, but the already-broken auctions didn't get flushed out of the database. I'll look into it. In all probability, everything is fine, and the code simply hasn't ran to finish the process.