My comment notifications seem to be disappearing into the ether of the Net -- half the time they show up in my email inbox, the other half they don't. If I don't happen to notice that the comment number for a particular post has gone up, I don't realize that someone has left a comment at all. (So if I haven't replied to a comment that's been left recently or I took quite a while to reply, now you know why.)
I've also been having my comments being eaten. I've gotten quite a few error messages lately saying the comment didn't post and been unable to recover the post by using the back-button, as I used to be able to do, necessitating my re-writing the vanished comments as best I can from memory.
I've also had problems in posting using the new update page interface. Posts are getting eaten and I have to redo them completely.
~~ puts coal in LJ's stocking ~~