[CentOS] imap on Centos 4

[Tony Wicks]

Hi all, I've been trying to upgrade a mail server from Centos 3 to 
Centos 4, the machine runs imap with local users only. I noticed that 
the imap-2002d-11 package does not exist on Centos 4 and I'm guessing 
that cyrus-imapd is a replacement. The problem is that users cannot 
authenticate to cyrus -

May  7 06:32:14 #removed# imap[14650]: badlogin: #removed# [#removed#] 
plaintext #removed# SASL(-1): generic failure: checkpass failed

Can anyone point me in the right direction ? thanks