Rick should look at this. You've got a pretty high number of posts but geez. If I'm reading this right it's counting how many posts are in ubbt_POSTS and and how many topics are in ubbt_TOPICS for forum 14 that are approved and have been posted since 1203364960.
Shouldn't be a big deal. It's only 91k rows. It's scanning all of them though, but still it's only 91k rows.