While typing a message I get auto completing when it guesses what word I'm going to type. The way you let it fill out that word is by hitting tab. Since the last update of the forum software, it will fill out that word but then jump to the element tool bar. Basically, making it a pain to use the auto completion.
I seriously doubt anyone uses the tab to go around to the different elements in the comment box. I wish they would put it back to the way it was before.