I can understand how something you have to really make an effort to blow up does not make the urgent list. It would never have occurred to me to go about running random startup scripts manually. I am not a Linux Hacker - but neither are most other Ubuntu users. My reaction to "hm, installation/upgrade did not work" would be to revert to the old version.

Not dissing the people who try to find the errors and fiddle around - they are the ones who advance the state of Linux in the long run. But it's probably a good idea to use a test system for fiddling around.