Removing sleep and hibernate buttons from kickoff

[Roderick Johnstone]

Hi

I'd like to remove the sleep and hibernate buttons from the kickoff 
Leave screen to prevent systems being shut down inadvertently by 
clicking on the wrong item.

I tried the recommendation here:
http://www.linuxquestions.org/questions/linux-general-1/disable-suspendsleephibernatewhatever-you-call-it-702553/

about changing /usr/bin/pm-is-supported
but that doesnt seem to remove the buttons for kde 4.4.0

Anyone know how I can remove those sleep/hibernate buttons.

Thanks

Roderick