I've spent a while wondering how to answer Mirco's response from the developers; Breck was right on the money as usual. It sounds like the solution was more complicated than necessary but nevertheless as long as I don't have to put up with that box coming up I'll have to be content.
Whether any tool should commit on disconnect by default is well and truly debatable but I guess we'll just have to accept that the developers of DBISQL think it's a good idea.
Thanks Chris.
Paul