It stopped being a problem for me anyway because I changed some config in my MTA (Exim4) for another reason which happened to mean that Procmail was no longer invoked in most cases. But I think it may be fixable in the Procmail space. What is in your /etc/procmailrc ?
Quite simple at the moment.
LOGFILE="/var/log/procmail.log" DEFAULT="$HOME/Maildir/" MAILDIR="$HOME/Maildir/"
I also notice some permission issues, no matter if I use a global procmailrc or one in user's homedir. It complains not being able to write Dovecot's log file. In practice, I had to force the following permissions:
666 /var/log/dovecot.log 666 /var/log/procmail.log
