TorrentG, I know you don't use a UPS but not showing the message isn't an ideal solution. If the power goes out for an extended period, the APC tells the computer to hibernate to force proper shutdown without data loss - it can't do that without the hibernation enabled.
I don't have a good answer for you brkkab, you may have to decide which happens more often and which you can live without
I would definitely check all your settings for power management in device manager and see if you can't somehow get it to stir when hibernation is allowed to occur. Otherwise you may have to upset the APC as TorrentG suggests.