Hey no problem. I also made a thread about the Dovecot issue. What I did was uninstalled bind and dovecot :
yum remove bind dovecot
And then ran:
And it configured for Courier and MyDNS, and I not longer got the dovecot errors like you and I previously got.
I don't know if the tutorial installs bind and dovecot, or if it was a default package installed. I think it might be worth making a note in the tutorial (if it isn't already there; I didn't see one) to uninstall bind and dovecot for a ISPConfig 3 server since it doesn't seem to support those services.