SuperDuper is a Mac OS X application from Shirt Pocket Software that creates perfect duplicates of your hard drives for backup and restoration purposes. The "Failed to Enable Ownership" error can stem from a number of issues, most of which can be resolved without seeking technical support from Shirt Pocket.
Every Mac OS X installation has at least one administrative account, which is allowed more access to the hard drive than other standard user accounts. If your Mac has only one user account, then it is automatically an administrative account. If you are logged in using a standard user account, you may be asked to enter an administrative password before running SuperDuper. This is required to allow SuperDuper access to all of the files stored on the internal drive. If you do not have an administrative password, ask the person who set up the Mac for the password, or reset the password using the Mac OS X installation disc.
External Drive Permissions
External drives are a special case for Mac OS X permissions. When an external drive is used as a boot drive for one Mac, and as a secondary drive on a second Mac, special handling may be necessary to resolve ownership permissions on the drive. Select the drive in the Finder and choose "Get Info" from the File menu. When the drive is not being used as a boot drive, a checkbox for "Ignore ownership on this volume" appears at the bottom of the Get Info window. Check that box and try SuperDuper again.
Shirt Pocket has documented cases where a bad installation of Mac OS X can cause an error to occur when attempting to read from the boot drive. Upgrade your version of SuperDuper and try to launch it again. If that fails, use your Mac OS X installation disc to archive and install a new copy of your version of Mac OS X. This will not affect your personal files. You should also run Disk Utility from the Utilities folder to ensure that you do not have problems with your hard drive.
Contact Shirt Pocket Support
If the problem continues after the above troubleshooting steps, contact Shirt Pocket Software customer support from the website. Shirt Pocket provides pre-sales and post-sales support.