Not a question - a story!
I reported some problems recently after 9/11/00 updates (51652) and thought it best to uninstall and re-install Norton AV, partly because I had run into a new feature of being cut off every time I used Live Update.
Yes, without doubt Norton AV updates had gone funny!
Cutting a very long story short I toured the Symantec site and it was suggested that I knocked out "connect to internet using modem" from Control Panel/Internet (whilst on-line). This caused a small "program update" to arrive.
I tried Live Update again (having restored the connection bodge) to see if it now worked and it did, but then offered me another update. I went for this but my virus definitions remained the same - probably because they are the latest.
So I tried yet again and this time a 1.4Mb update came down, still leaving my virus definitions at 9/11/00.
One more try and it said all was up to date. Great - I'm happy.
Not all of my problems went away but I have invented various work-arounds to use while they get their act together (some are worth keeping).
So the moral of this story is "if at first you don't succeed, try, try and try again - I reckon Norton are having a real bad time.