Launcher icon (under Unity) gets duplicated

[mandyzhou]

I have SkypeTab locked to my Unity launcher. When I click on it, another SkypeTab icon appears directly below it: http://i.imgur.com/RSaDX.png It appears that the running instance is the lower icon. I've tried unlocking the top icon and locking the lower icon, but the same thing just happens again the next time I start up SkypeTab.