brokencrow,
Unfortunately everyone whose replying is correct. Hindsight is always 20/20 though...

In any event, I work with Symantec CE as well and have had some very annoying upgrade issues. Just upgrading from 10.1.1 to 10.1.5 was a bastard of a process. Vista machines needed a separate 10.2 upgrade (the 10.1.5 doesn't work with Vista machines)...it goes on & on. After one particular upgrade, we had machines that couldn't contact the server, we had one server take a sh*t. Sigh.

While I like Symantec CE products, I think they need to revamp their upgrade solutions (Not to mention, their licensing portal is also a pain in the arse).
And, even though I'm not experiencing what you are currently dealing with, I'd like to know how it turns out and what the culprit is. Best of Luck.