Supposedly the thread already has 10 (or multiples of 10) posts. I use quick reply to make a new post in the thread that would basically add a new page to the thread. The editor gives up after a few seconds. Thread is not updated. But the post is indeed made in the background. If the user tries to post again, it results in double post.
I am on Dreamhost and I have a feeling that their MySQL server assigned to me is overloaded. Can this be the reason? Any suggestions would be helpful.