From Apple's site:
Disk Utility can't verify or repair permissions on the Mac OS X Panther volume if the "BaseSystem.pkg" file is not in /Library/Receipts.
This alert appears when you try to repair permissions with Disk Utility:
"First Aid failed
"Disk Utility stopped repairing permissions on '(volume name)' because the following error was encountered: No valid packages"
In the Disk Utility text window, this message appears in red text:
"Error: No valid packages (-9997)"
This happens when the BaseSystem.pkg file is not in /Library/Receipts.
Solution
If you've moved this file, move it back to /Library/Receipts. You shouldn't normally remove any files from /Library/Receipts.
If the file has been deleted, replace it by copying it from a different computer that uses Mac OS X Panther, or by reinstalling Mac OS X 10.3 from an installation disc.