Downloaded the updater a few hours ago and used it to burn a new CD containing DiskWarrior 3.0.3. The updater worked like a charm. Booted from the CD to examine my hard disk which I'd updated to Tiger (Delete and Install) about a week ago but which crashed erratically (endlessly spinning pizza). DiskWarrior discovered over 40 errors on the disk which it repaired. I've now rebooted without a problem although it's too early to know whether the erratic behaviour has been rectified.