when i press and hold on icons. sometimes the icon stucks on the mouse

[Ismael]

I use Docky program it's a dock application, when I press and hold the icons of the programs and moves them from this dock application, the icons stuck on the cursor.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.5+14.04.20150603-0ubuntu1
Uname: Linux 4.1.0-040100-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.11
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Wed Jun 24 14:55:38 2015
InstallationDate: Installed on 2015-06-23 (0 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)