My macpro keeps asking me if I am sure that I want to shut down. This is happening every minute. I am not however going to the finder and choosing shut down. It is happening on its own. Any help please. Thanks.

It is not happening like clockwork at precisely one minute intervals, but immediately after I respond 'cancel' to the question "Are you sure that you want to shut down". After 10 minutes of this, I just walked away from my computer for a while and when I came back responded cancel one more time and the messages suddenly ceased and haven't reoccured for about an hour now.

I am the sole user of this computer so no one else is playing with the system configuration. It is on a wireless network, but I am the sole user and the other computer, a macbook pro running snow leopard, was not receiving this message.

Time machine backs up this computer, a macpro running lion, but not the macbookpro incase this has any relevance.

Well it has been about 6 hours since the message stopped happening. I never tried disconnecting the keyboard, it just went away on its own. Mayble the shutdown messages were a fluke and the OS just fixed things on its own, I don't don't know. I am waiting to see if the message starts reoccuring. If it reoccurs I will try unplugging the keyboard, but I am curious how this could be causing the issue? I am using a wired apple keyboard, one of those chrome models. As far as I know there is no key on it that shuts down the computer and I didn't set one up either.

Perhaps the message is left over from my manually shutting down the computer yesterday. I had first tried to shut down the computer by the normal route of going to the Apple icon and choosing shut down, but finder had cancelled shutting down because of unsaved changes in time machine so I manually shut the computer down by pressing the power button.