Do you see the @ sign in the userlist in the irc client?(located on the right hand side on mIRC)
I you don't, then you have to wait until you see a message like "jtv sets mode: +o <mod_nick>" or the @ sign before the <mod_nick> in the userlist.
Twitch's IRC servers usually do not instantaneously give +o to mods. It can take up to 1-2 mins..
