any way to disable prompt for open tty during shutdown

[Paul S]

If I happen to use a console (tty) during a kde session, I get a prompt 
during shutdown to cancel / continue for that tty.  I'd like to disable 
this feature.  For me, when I hit shutdown, I want to be able to hit 
return and walk away and have it work.   Whenever I forget that I had a 
tty open, I've come back hours later and it's still hung on that prompt. 
  Not a secure feature imo.

Anyone know how to disable this?

I'm running lucid kubuntu now, but have had this on karmic too.

TIA