Sorry, we are still having the same issue. Even though EPG scanning was not running, the channel was already being played. When you play the channel again, we still get this message: "Already playing this channel, returning without further ado". It appears that a tuner is stuck to that channel and was never reset.
Are you using the "Media Server" feature? In other words are you letting MC Media Server to start automatically when Windows starts? If so, Media Server will continue to run when you close MC GUI. This would explain why you keep having the "tuner already playing the channel" issue. To close Media Server after you closed MC GUI, you need to right-click the Media Server icon on Windows control bar, and choose "Close Media Server".
You can check the status of tuners in Standard View by clicking "Show status" in the Standard view EPG filter box. It will tell you the status of each tuner, idle or otherwise.