I found the same thing and posted in a different forum probably my bad, but here is what I did to get it going.
/etc/init.d/courier-authdaemon start
/etc/init.d/courier-pop start
Then to make sure it starts automatically in the future:
chkconfig --add courier-authdaemon
chkconfig --add courier-pop
Think that is all that is needed, but I haven't played with it past this point. Still reading the ISPconfig pdf.
Hope it helps
