Killing app/process programatically

Hi,

I've got a problem.

I want kill app in C# .net.
I've tried this class :
http://www.codeproject.com/Articles/...-supports-full

And this programm wich /kill switch :
http://www.dotfred.net/TaskMgr.htm

But not work :(
App crash and i'm forced to reboot may device.

But when manally run Windows default TaskManager and kill app It's ok !

Please help me :)

Thanks