strange behavior which seems to be a double post but is not

[tvb]

I noticed this before on my own forum but now on esoTalk as well. After posting a reply the result is that it looks like the previous post became a double post and my reply is not visible. See below

Original post to which I am reply:

After posting I am not seeing my reply but seeing the original post as a double post (note the missing avatar indicating a second post by the previous poster)

However, when I refresh the page my post is visible and the double post is gone.

I have no idea what is causing this!

[hugeping]

Hello! In fact, i can reproduce this bug sometimes.
Open two browsers and login user1 and user2.
User1 writing comment, but not submit in thread A.
User2 writing comment and submit in thread A.
User1 in thread A see extra own message, while js code updating thread.
After refresh, this doubled post becoming post from user1.
Hope, this helps.

[tvb]

Got it again today:

Screen after posting:

Screen after refresh:

[inliquid]

This happens when you post at the same time with ajax which is constantly pulling the server for new posts. I have noticed this behaviour some few months already.