Boots into wrong HD
I have a problem that only happens occassionally. I have my Mac Pro set up to boot at a certain time every morning using the energy saver schedule feature. I have also set a disk I've named "Lion HD" as my startup disk. I also have a disk named "Lion HD back up" which is an exact bootable clone created with "super duper". Every now & then the computer boots into the Lion backup rather than the Lion HD. Any ideas why this happens & what I can do to fix it?
Mac Pro, Mac OS X (10.7.4), 8 gig, 30" cinema