procmail and sendmail <what is going on?>

Hi, I have Sendmail installed on my RH 6.1 server.  I have been trying to get 
procmail running now for three days.  I have modified the sendmail.cf , the 
file permissions are correct.  The problem is when an email is sent to an 
account the .procmailrc does nothing, not even a mention in the log file.
Can anyone help me?
Thanks
Andrew