Ubuntu: Icon sticks to cursor [closed]

My cursor ends up dragging an icon around the screen, after some time of use. I'm running Ubuntu Gnome, and I'm suggesting that it has something to do with Docky, since the icons are coming from there.

Simply put, what happens is I make a tap or a long press on my left mouse button over an icon in Docky, and drag a little or a far, and the icon sticks to the mouse.

Is there anything I can do, to make this go away for good (a reboot is removing it, of course), or just be able to "clear" the cursor, without having to reboot?

This happens to me occasionally, but I just lock my screen and unlock it, and then the icon problem is resolved.

Start Terminal (Ctrl+Alt+T) and write command:

pgrep Docky

I had the same problem. But when I wrote above command in Terminal got it resolved.