I've seen the same thing. I went through disabling... let's see..
AutoBar, AutoTurnin, BigWigs, Eavesdrop, Decursive, sct, FuBar and then finally Gratuity allowed me to duel.
Too many to keep turned off, turned 'em back on, I'll wait for someone to figure out whats really wrong.
So someone who really likes to duel..
