It may be stuck occasionally and after a few seconds of inactivity this may occur. It's similar in all browsers, without addons. It may depend on the thread, e.g. I believe I saw it on an old thread (2 days old).



- - - Updated - - -

e.g. I saw it in this thread right now http://www.mmo-champion.com/threads/...-AOE-fire-mage

- - - Updated - - -

Aha! I found a workaround. If the quotation is removed entirely, it works! Then if I edit-in the quotation it saves it.

Very peculiar.