Running NetBeans from Unity launcher gives you two icons for NetBeans

When you add NetBeans desktop file to Unity launcher and run it, you could get two icons for NetBeans.
Steps to solve this:
- remove NetBeans from launcher
- add StartupWMClass=NetBeans IDE 7.4 to desktop file
- add NetBeand back to launcher

This is how my netbeans.desktop files looks like:
[Desktop Entry]
Encoding=UTF-8
Name=NetBeans IDE 7.4
Comment=The Smarter Way to Code
Exec=/bin/sh "PATH_TO_NETBEANS_EXEC"
Icon=PATH_TO_NETBEANS_ICON
Categories=Application;Development;Java;IDE
Version=1.0
Type=Application
Terminal=0
Name[sl]=NetBeans IDE 7.4
StartupWMClass=NetBeans IDE 7.4
OnlyShowIn=Unity;
X-UnityGenerated=true