OS X 10.4.9 and backup to disk image failure

[macWish]

Before updating to 10.4.9, I had made backup User Files from my iMac to a sparseimage on my MacBook over local network. No problems with initial backup or smart updates.

Then I updated both machines to 10.4.9. Subsequently, I made a smart backup of my user files without any apparent problem reported by SD. However, when I tried to mount the sparseimage on the MabBook, I got the following error message: "Disk image you are opening may be damaged..." According to Apple Knowledge Base article (http://docs.info.apple.com/article.html?artnum=305111), OS X 10.4.9 is more robust in its ability to detect damaged or corrupted disk images." I followed the suggested work-around of the article. First I duplicated the sparseimage with Disk Utility. Then I attempted to perform a disk repair of thedisk image with Disk Utility. The repair was unsuccessful and I got the following error message in Disk Utility:

"Verify and Repair disk "iMac Backup"
Checking HFS Plus volume
Checking Extents Overflow file
Checking catalog file
Invalid sibling link
Volume check failed.

Error: The underlying task reported failure on exit.

1 HFS voume checked
The volume could not be repaired because of an error.

So the question is: what next? Do I just make a fresh networkup backup to a new disk image or is this a OS X 10.4.9 problem that interferes with the function of SuperDuper?

[dnanian]

Looks like the image is damaged... I'd delete it. SD! will automatically recreate next time around.

(It's not a 10.4.9 problem; this is damaged at a low level that must have happened due to a bad shutdown, connection, etc.)

[macWish]

Fresh backup to sparseimage went without a hitch and the disk image mounted on my MacBook without a problem. The peculiar thing with the previous backup was that I don't know how the disk image could have been damaged as I had not shut down the MacBook and had no problems during the Smart Backup. Mysteries are a nuisance.

[dnanian]

They are, I agree. But it's low-level damage, so likely to be a low-level problem...