MailScanner / Postfix anomaly

[Patrick Healy]

Hi,

I just finished an CentOS 6.2 installation followed by Postfix and then 
MailScanner.  All seemed to be going well until I stopped MailScanner 
and then restarted it.  For whatever reason, Postfix refuses to start 
and kicks out the following error:

fatal: unable to set session and process group ID: Operation not permitted

However, when I start them individually (i.e. postfix start; 
check_MailScanner) both subsystems start and mail is processed.  Can 
anyone point me in a direction to start looking?  I'm trying to wean 
myself off of Sendmail, so I'm relatively new to Postfix.

Thank you,

Pat