I haven't been receiving comment notifications in my email since lj made the big format change in Fall of '08. I haven't been able to tweak it back to normal, and can't be bothered to do more. So if I don't get back to you right away, or at all, that's why. Typically I've been checking to see if someone made a comment back to me, but if you commented on something I posted or commented on some time ago, I'll likely miss it.