System won't shut down; Logs off instead

[flyingsolo]

I'm using 12.04 in dual boot with windows 7. I can't recall when this started but sometime in the past 2 months approximately, if I try to shut down or restart the computer from within Ubuntu, it only logs off my current session. I cannot force it to actually shut down without doing a hard stop (ie: power button).
I haven't been tweaking the system in any odd way so I don't know how this got introduced. I do need to shut down or restart when I want to enter the windows world for work purposes. Otherwise, the computer is almost always on in Ubuntu and used for general purpose computing & provides in-home media repository.
Any ideas of how to correct this would be appreciated as I hate to repetitively need to do hard restarts. Thank you.

[2F4U]

Can you shutdown from a terminal? Open a terminal and enter

sudo shutdown -h now

[flyingsolo]

Can you shutdown from a terminal? Open a terminal and enter

sudo shutdown -h now

Yes, this does perform a proper shutdown of the computer.
So, thanks, at least I don't have to keep using the power down button.
But, still, what could have occurred to change the usual manner of shutting down? I have gone to 'suspend' sometimes; could that somehow introduce a problem? (it comes out of suspend just fine)

[flyingsolo]

Still looking for more help, please.
Thanks to 2F4u for the command line method to shutdown the computer but still, what could have gone wrong with the standard method of shutting down from the panel button?
Any suggestions would be appreciated.
thanks

[offgridguy]

Do you have more than one user account? If yes, you have to log out each user account to
shutdown.

Thank you 2F4U for that useful bit of information.

[flyingsolo]

No, just me as user.

[offgridguy]

No, just me as user.

Well that takes care of theory #1.
Does it make any difference if you log out first, then try shutdown?

[flyingsolo]

Just caught up to your reply now.
No, it doesn't matter if I log out. In fact, when I try to shut down, essentially it just logs me out of the current session and then from that screen, if I try to shut down, nothing happens and I am left at the same log in screen.

[yoramdavid]

If I may use your threat as well, I am experiencing the exact same problem. This happened after upgrading to Ubuntu 12.04.

[BLNCNMRQ]

If I may use your threat as well, I am experiencing the exact same problem. This happened after upgrading to Ubuntu 12.04.

I am having exactly the same problem. It occured a couple of days ago.