When shutdown, system hangs after i installed a program.

[Art?!]

Hello!

I have a problem. Almost every time when I installed a program, the next time when I restart or shutdown my pc, the system hangs. I only get too see my background and a spinning circle. These are the result from the console:

5/15/08 5:46:58 PM com.apple.loginwindow[39] Shutdown NOW! 
5/15/08 5:46:58 PM com.apple.loginwindow[39] System shutdown time has arrived 
5/15/08 5:48:45 PM com.apple.launchctl.System[2] launchctl: Please convert the following to launchd: /etc/mach_init.d/dashboardadvisoryd.plist 
5/15/08 5:48:45 PM com.apple.launchd[1] (org.cups.cupsd) Unknown key: SHAuthorizationRight

5:46:58 PM is the point when I restart.

Can someone help me?