10.7 boots into a Recovery partition (command c boot) then can check the condiiton of other partitions on the drive.
To repair the entire drive it the computer needs to be booted from Lion w/Disk Utility on a external drive
Either use Carbon Copy Cloner and make a option key bootable clone on a blank external drive and use Disk Utility that way or create a data recovery drive
Must be that you have FileVault activated. This happen to me this Week End.
I spend time to backup, reinitialize and restore my Hard Disk. Everything was fine until I ractivated FileVault.
So I presume it's a false error detection in Disk Utilities application.
I see another discussion on the same topic: Error: Storage system verify or repair failed