I have exactly the same problem.
First, it says nowhere that it needs to be activated!! This has to change.
Second, when I figured it wants to connect to the internet I allowed it, then of course I got the infamous "Could not write activation signature" and I wonder why we get this message, after *one* try to connect without success. How can this be? Should be changed as well.
Third, I tried several times of course (until I found this thread), and seems I have the next problem now, "Maximum activation count reached".
Geee, thanks, I upgraded last week. If I had known I'd run into these kind of troubles I wouldn't have bothered at all.
@Mike: your instructions did work, they were correct for me, but unfortunately I have the next problem now. Can it be reset? Before I go and write an email

....
Thx.