NickServ tells me that the AUTH code is incorrect. What should I do?
You should first be sure that the number you have entered is correct. This is why copy and paste is recommended whenever possible. It may also be possible that you have changed your email address and are entering the number for the former address. Please read the entire email you receive to be sure that the number you are entering is the AUTH code for that nickname. In setting emails for several nicks, confusion like this could easily happen. In addition, if you have changed your email address since the last registration, a new authorization code would have been sent to the second email account. Only this new authorization code will work to complete your nickname registration. You can also request another authorization code from services by resetting your email address with the SET EMAIL command (section 4). If NickServ tells you that you have already set the email address then you can get around it by specifying a bogus email address before setting it back to your real email.