-Level 20 orc warrior -Already tried clearing WTB, deleting chat cache in WTF, /reload, /leave then /join, and restarting wow. I just stay in the channel I was in before (/s /g and /p work).
Sometimes it goes all wonky on me too. If you are certain that it isn't any addons messing with you, try using combinations of the numbered and named channels. /1 /general /2 /trade /3 etc.