I canceled a sale once before also. The buyer paid immediately, which is very unusual, so I figured it would be a quick transaction. Sedo asked me for the AUTH code, which I sent within hours. 30 days go by, with absolutely no further action and many unanswered emails to Sedo. It was only a $70 sale, so I wasn't too worried about getting the money, but the whole process was angering me. I got a random email for the domain offering about the same price so I sold it within the day. I than emailed Sedo to tell them I was canceling the transaction and magically received a transfer request (well, the new owner did)...
I emailed them and told them that I no longer owned the domain and that I had sent the AUTH code over a month ago and many emails and had never heard a single thing back from them. They didn't threaten to review my account or anything of the sort. In fact, they really didn't say much at all. What are they going to say?
Since Sedo handles it's own Escrow, I imagine they purposely stall transactions to ensure that the money they receive is valid. I'm sure they've taken a few hits from fraud. Still, they either need to start providing good service or get out of the business...
Sedo pales in comparison to Afternic in my opinion, on many points.