Two xScope icons appear in my dock. How can I fix this?
 

This is an issue caused by a frequently-requested feature by our users: hiding xScope's Dock icon.
 

When you have this enabled, and you add xScope to your list of login items, this issue will arise. The only permanent solution to the problem at the moment is to remove xScope from your list of login items. If you don't wish to do this, you can temporarily fix the issue by restarting the Dock via the Terminal. To do so:
 

Open Terminal and enter: sudo killall Dock
Enter your administrator password and the Dock will disappear and reappear without the second icon.