I was getting the same errors, but my wife was able to update without incident.
I went to Norton's site and found the following...
»service2.symantec.com/SUPPORT/sharedte..[?]
Basically, the article explains that one of the reasons for the "6002" error is that if you have corrupted DL'd zip files, it won't work properly. How they got corrupted, I don't know - but when I deleted the files in the directory as suggested by the article, I was then able to perform a successful Live Update.
Interestingly, before I deleted the files in the
C:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdate\Downloads directory, there were four files...
liveupt.sig
liveupdt.grd
livetr.zip
autoupdt.trg
After running LU, there is now only one file...
livetr.zip
I hope this helps.