rogue MailScanner processes

[hermit921]

I have 4 RH9 boxes running MS 4.24.  The install process was the same on
each, and I copied the config files from one box to all the others.  After
2 weeks of operation, one of the boxes began to stop delivering mail at
irregular intervals, although postfix kept accepting mail and storing it in
the postfix.in queue.  Stopping and starting MailScanner would start the
mail being processed again.  I noticed that although MS is supposed to
restart itself every 4 hours, when mail stops I find older MS children
using 80-99% CPU each.  Sometimes killing just one of the rogue processes
is enough to start mail flowing again - I suspect that would always work if
I selected the correct process.  Any ideas where to look?

hermit921

# ps -ef |grep Mail
postfix   6399     1  0 Nov02 ?        00:00:00 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf
postfix  16265  6399 81 Nov02 ?        20:24:40 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf
postfix  16435  6399 81 Nov02 ?        19:57:56 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf
postfix  21172  6399  0 09:01 ?        00:00:10 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf
postfix  21431  6399  0 09:03 ?        00:00:04 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf
postfix  21491  6399  0 09:03 ?        00:00:04 /usr/bin/perl
-I/usr/lib/MailScanner /usr/sbin/MailScanner /etc/MailScanner/MailScanner.conf