I think the emails from the blog/gallery system which should be sent when someone leaves a comment on your blog entry or photo are broken. I haven't been receiving them for a while and Martin hasn't either. So if you rely on these emails to know when someone has commented... well don't! You'll need to go and check from time to time. The new blog/gallery system should fix that as it is a proper part of vBulletin. I won't be trying to fix the current system.