This took me a long time to figure out. There are some tips here and elsewhere providing fixes for FileVault problems caused by sparse image corruption. I discovered today that similar problems on Time Machine sparse image files were causing reproducible kernel panics (KPs) on remote Macs backing up to these sparse image files via a server Mac. The problem is that there's very little indication to lead one to that conclusion. I was getting predictable KPs as soon as Time Machine backups would begin, and none of the disks involved (remote computer, server computer, attached USB Time Machine disk) showed any problem at all with Disk Utility or DiskWarrior.

The solution was to log in as root on the server computer, and then use the following command to attach (but not mount -- this is key!) the image:

hdiutil mount -nomount -readwrite /Volumes/path/to/sparse/image

I then used DiskWarrior to rebuild the directory. (Disk Utility aborted with a sibling link error or something like that.) Without DiskWarrior, I would have had to delete the entire sparse image file and start a new complete backup series. This not only demonstrates an obscure vulnerability of Mac OS X 10.5.2, but once again reminds me I'm glad I ponied up for DiskWarrior. (More detail at can be found in this post on Apple Discussions.)

[robg adds: Obviously, this hint isn't something that's easily tested. It's posted more as an aid to those who may be experiencing kernel panics for no apparent reason. If you've seen such issues yourself, please post in the comments.]