Originally Posted by BeccaPrice
My computer has wifi, but it's hard-wired in. I do have a wireless mouse - could that be causing the duplication?
Your mouse has nothing to do with it. If your computer's wifi is active and connecting to your wireless router along with your computer being wired then your CC will see two paths (one wired and one wireless) to your calibre install and report seeing two instances. Check out all of the icons in your task bar, one probably shows you connected via wifi. Disabling the wifi connection (on your computer) will remove the duplicate instance of calibre that CC sees.
If this is a laptop you take on the road be aware that you will have to re-enable wifi if you want to link via wireless away from your house.