persistent Grey square on the top left hand corner of the screen while doing to drag and drop

[piruthiviraj natarajan]

I use rawhide and whenever I drag and drop the files using nautilus or
nemo  there is a persistent square on the top left hand corner of my
screen both in gnome-shell and xfce. It disappears with closing of the
file manager.
can you guys help?
here is the screenshot.
https://dl.dropboxusercontent.com/u/106654446/Screenshot%20from%202013-05-06%2010%3A24%3A56.png