After having successfully completed 3 OSX 10.6.3.1.1 updates, I finally hit a snag on my daughter's Ice Blue. Did everything according to Hoyle (whomever that is), and it booted all the way to the home screen, but failed to load the task bar, the desktop icons, or the dock. Damn! I tried everything, "recovery=y," "-x" (and when it tried to boot into Safe Mode, it was stuck in some kind of a diabolical reboot loop), and finally "-v" to see the problem (which was never apparent).
Ultimately I removed the HD from Ice Blue and subbed it into a USB HB drive housing. Then, moved the critical and personal files (in the user) area to my MPB, reinstalled the HD, reset the partiton, and did a clean reinstall with NBBM 0.8.4rc1 (saved her music, which was the real crisis at hand). All is well, but I still don't know what went wrong on a garden-variety, usual update. Oh, well.