It's just a minor glitch/time out session. Just press "post" again after making sure that you've not posted it earlier. ^^ It happens to everyone.
i do.. just it someone the website crashes and comes back on then um not able to comment anymore right after
Yeah, at times the whole website crashes and you need to refresh the page a few minutes later.
I'm not sure what the whole issue with not being able to post shortly after is though.
Ever tried refreshing the page fully again?