I've had this happen quite a few times on firefox, primarily when I go to post in the gifs and such thread. I instead head to a different thread and "set up" the post there (I'm far too lazy to type out [im
g][/img] at the ends of the links :
D) then just copy/paste in the proper place.
I don't use Chrome much anymore but I did log in on it to see what happens and yeah, it's far worse on there. Get the above on loads of different threads, though sometimes the buttons and faces do magically appear after a few seconds.