I have a WCF service and 2 clients I'm testing with. The first client is written in c# .NET 3.5 and has no trouble connecting to the WCF service. The other client is written in Delphi7, and it's the one I'm interested in getting working. This is the interesting part. If I start the service then hit it with the Delphi client, it won't connect... but if I start the service then hit it with the .Net client then try the Delphi client, it works ! Could be something to do with the design-time addresses, I'm not sure. Maybe a more experienced person will know what's going on and what I need to do to get my Delphi client working without needing a .Net client running alongside it. It might be relevant to note that the service is currently being hosted in a winforms app.
regenerating the wsdl and re-importing it into Delphi 7 seems to fix it.