Post counts and archiving/upgrading?

[Chris M Jenkins]

Since upgrading to IPB4, my users' post counts have gone down dramatically. I don't know if this is because the upgrade has rebuilt everyone's post counts, so any deleted posts have been lost from their post counts, or if me turning on the archiving feature (which I did pretty much at the same time as upgrading) has caused any archived posts to be removed from people's post counts.

Either way, quite frustrating for members who were very proud of their post counts. Does anyone know which of the two things may/will have caused this? Cheers!