By mistake I make some changes to important system files to bring transparency effects once, installing Gnome shell 3.6 in Linux Mint . I don't remember exactly what i did but due to this all the icons in application area of Gnome-Shell were appearing twice.
Hence here are some of the steps may help you resolve the problems:
- Open /var/lib/menu-xdg/applications/menu-xdg from that window.
- All the files have their name with the extension .desktop
- Now open terminal and change the directory to that particular drive
- Type sudo rm *.desktop
- Open /usr/share/applications delete duplicate icons or unnecessary icons from here