I had a problem with my GPS not working last week. I attempted to fix this by uninstalled a cached area in G Maps, then I uninstalled all updates to G Maps. Bootloop ensued.
It would happen so quick that I could not get into the dialer to do the fix before it would reboot. So despite not having done a back up recently, I had to do a factory reset from HBoot. Never again, so I finally rooted last night.