How to shutdown/reboot Ubuntu 10.10 without having to leave the login screen (possible solution)

Hi everyone I will explain what I did when all was well on my ubuntu 10.10 until one day off and wanted nothing more I closed meeting (is a nuisance off from the login screen), The problem is that another session was initiated from my laptop how? because the problem was a program installed called freevo (which is a media player in the style quick hp). Search and browse anything until sometimes I