Intermittent - Won't shut down / Arcade page comes up on startup

My one-year-old Acer Aspire 6920 has recently begun giving me problems when I try to shut it down. Sometimes it shuts down properly, but other times it says it is hibernating and then reboots. Once I tried five or six times to shut down, but it came back alive like a vampire. I finally had to do a hard shutdown with the power button.

I have checked the shutdown settings and have tried shutting down with every type of shutdown icon I could find, including the Start button and the Ctrl-alt-delete, then Shut down button or dropdown menu . On the Start button menu, what I seem to remember that used to be the Off button (red) is now a Hibernate button (orangish brown).

Also, when I try to start it back up, it often opens with the Acer Arcade, but without the usual minimize/exit buttons in the upper right hand side. I have to go to the center and click on exit several times or hit the escape key.