[gpm] odd behaviour

[Brian Russ <bjrus cooptel net>]

I noticed a few days ago that my desktop machine (which I use most days)
had switched itself on in the middle of the night. This was mystifying
because the only change I had made recently was to accept some security
updates in the usual way. Now I notice the new Notification icon in the
top panel and the power  management facility includes the battery stuff
that is irrelevant. The worst thing is that Shutdown no longer means
that - the machine switches itself on again immediately. This is bad
because my Dell Vostro has a power button that only ever switches ON. I
shouldn't have to pull the plug !  can I get back to the previous, easy
set-up ?
thanks in anticipation,  B J Russ