Disk Utility Restore error: "Recovery partition restores can only be done on GPT partitions"

I am trying to make a backup image of my Lion Server to a backup drive and in the past the "restore" feature always worked but this time I got an error saying "Restore Failure: recovery partition restores can only be done on gpt partition maps"....Why is this error showing up now and why can't it back up my system? I have the backup drive formatted as Mac OS X Journaled and it worked fine for 10.6 so I don't see the issue...