How Post Count is Calculated

[tsptom]

I have a question about how post counts are determined. I have one member who has 5042 posts, according to the database using this query:

SELECT count(*)
FROM post
WHERE username = 'xxx'

But that gets 42 more rows than what the post count in the forum is, which says 5000 even.

The "visible" field has 5039 1's and 3 2's, if that means anything.

What would cause the difference?

Thanks.