Where has my "close, hide, maximize" options gone?

[GameDog(A)]

I had a problem upgrading to 11.04 so I uninstalled it and now when I log on under "Classic Ubuntu" as well as regular Ubuntu sessions for some reason my Close, Minimize, Maximize options are no longer available. How can I get this back?

[Krytarik]

Please see this troubleshooting guide:
http://ubuntu4beginners.blogspot.com/2011/04/missing-top-and-side-panels-in-unity.html

Greetings.