Dustin J. Mitchell wrote at 21:14 -0500 on Sep 26, 2007:
 > Just a guess -- is this a Linux machine that recently had hardware
 > added/removed?

linux, no - freebsd.  devno changes?  I don't think so.  There was a
raid disk replacement.  But that's a hidden device behind an LSI
Megaraid controller that exports the raid as a scsi device.

 > If so, the device numbers may have changed for that partition, leading
 > tar to think that all files have been changed.  Gene Heskett chased
 > down such a bug several months ago.

I'll check for devno changes on the scsi device.