I know this is an old thread, but I'm having this exact same problem (the option for changing mood is missing). The changemood.php file has the line in it that Rick indicated it should. I opened it and resaved it, still no go.
I second the request for better documentation. It'd be very helpful to have a detailed help file for how to do operate any and every feature that UBB.threads has. If there is one, I'm sure missing it!
Thanks IA for your help.
