Might be a good time to point out a very valuable vBulletin feature: Ignore User.

Click the user's name in the avatar for any post of theirs.
Choose "View Profile"
Click "Add to Ignore List"

Voila... your thread reading will no longer be polluted with that person's posts. I make liberal use of this feature, especially over on ADVRider. Doesn't mean I don't like you; just means I'd rather read without having to read your posts.

You can view your ignore list via the Settings item that is in the upper right any time you are logged in.