I would love to help (and do pitch in the odd comment). However the three upgrades that I have done have gone relatively painlessly so I have no experience of most of the problems.
In fact the only problem that I do have direct experience of is Security Center not recognising Norton.
Having read a lot of these problems I am firmly of the opinion that at least some of these problems are caused by:
- installing SP2 on systems with crud on them
- not closing down all non-essential running processes.
Be assured, I do look in from time-to-time and try to help if I can.