So recently all of the smileys and HTML gadgetry disappeared from my reply page. If I click "attachments and other options", it just snaps to the top of the page. Also, the new-fangled expand text box (which is an awesome feature, btw) no longer works either. Lastly, I can't quote other posts once I've got the reply form open. I can quote from the thread, just not once I've already started the reply.
I figure there's some tick box somewhere in my profile or something, but I haven't been able to find it. I also switched from Core to one of the new themes, and there's no change. What's the next thing to try?