wp_list_authors behaving differently after upgrade to 2.2.2

The option count for wp_list_authors is showing me as having written 442 posts in my blog, which is way more than the actual number. I think it may now be counting Pages as well as Posts (although then the number strikes me as being on the low side).

Anyone know anything about this? Is there a way to exclude Pages from the count if, in fact, that’s what’s going on?