It seems that after the arrival of Leopard, some hard drives gave a problem without apparent solution according to the verification of the same in the Disk Utility. The system is working correctly and no files appear damaged, unreadable or anything like that.
This was my case since December 2007 after a little over a month from the update to Leopard until the moment of the installation of the update to its version 10.5.2, after which, the Disk Utility said that the hard disk of my MacBook pro did not have any errors upon verification.
The disk was always irreparable both from the Leopard bootable and from another mac by firewire in "Target Disk" mode and it always returned an indeterminate error.
Conclusion: update to Leopard 10.5.2 fixed false disk errors in "Disk Utility"