[CentOS] Pam problems

I'm having problems with what I think is PAM. Seems that ever since 
Centos 5, proftpd has had problems using pam, and with Centos 6.2 64 
bit, I had to quit using it altogether with proftpd.

Now I'm trying to set up SMTP AUTH using PAM as the pwcheck parm to 
saslauthd, and I can't setup new email accounts on my port submission 
(587) to work at all. We use this port of sendmail so outside users can 
send through our own email server. The crazy thing is that users that 
were setup previously before my migration from an older Centos 3 box to 
the new box can still use the port fine on the new server. But I can't 
get a new account to work. I'm not seeing any errors anywhere, but when 
trying to configure an account manually in Thunderbird, it fails 
whenever I use port 587. I've got a similar host on using old Centos 3 
that still works fine and I'm using it as a model along with the 
settings on the original Centos 3 host that was replaced for most of my 
parameters.

Anyone had any experience with sendmail and this sort of thing on Centos 
6.2? I've stared at this thing for days and tried about everything I can 
think of. The yum says pam is up to date.

I have at the least the same pam packages, if not more, on the new 
server as the old ones.

Any help would be appreciated.

steve campbell