[newbie] shutdown

[JK]

I am trying to get shutdown to send a warning message to other users... the command
should be something like
shutdown -k now mesg

But it just sends shutdown canceled.. on red hat system, that works and I never have
a problem... I tried it on 2 mandrake computers, and they both have the same results.
Any clue what I am doing wrong?

Thank you
JK