I would have thought that the Activity count would be that of 2, in accordance to the two posts made on Meta. While trying to figure it out, I stumbles upon a couple of weird additional Newbie cases:
a)
https://bitcointalk.org/index.php?action=profile;u=2744380This account has 7 posts according to the post count, but 0 Activity, and actually no posts in the “show the last post of this person” link. If fact, the account made at least 10 posts, all being deleted at some point (see
http://loyce.club/archive/members/274/2744380.html).
b)
https://bitcointalk.org/index.php?action=profile;u=2756879This account has 1 posts according to the post count, but 0 Activity, and actually no posts in the “show the last post of this person” link. If fact, the account made at least 2 posts, all being deleted at some point (see
http://loyce.club/archive/members/275/2756879.html). Additionally, this account is banned.
So there do seem to be some isolated circumstances that throw the Activity counter off its path.