Perhaps it's a bluetooth or wireless / networked device? I use Growl (a centralized notification system) + Hardwaregrowler (in the Growl dmg) on my MBP to notify me on changes. Perhaps you could give that a try to see what is actually causing these messages....
Have you put a Flash Drive or anything in the computer lately or is it randomly happening? If you have put a Flash Drive or something else in, try putting it into the computer and leaving it connected for a few minutes, then drag it to the trash can to eject it properly. Hopefully this works. If it does work, or it started happening randomly, I would go to your nearest Store.
I restarted my computer and that didn't work. It seems that when I plug in and external drive I get the message also and my computer no longer loads the device.