I hit this today. I had installed TwitterDeck on my machine, and I couldn't successfully get Jam's test suite to pass. Online setup tests specifically were failing. Repro'd it by running Jam and trying setup online. In the debugger, it was apparent that port 5005 on localhost was already in use. netstat -n revealed that that TwitterDeck was using this on multicast. The problem is that Jam gave no feedback that the port was blocked. Setup just failed. Unacceptable. There should be output at the console or a popup error dialog.