procmail <defunct>

[ZyanKLee]

I notice many defunctional procmail-processes after some time of running the server.

# ps -A | grep procmail
 3659 ?        00:00:00 procmail
 3730 ?        00:00:00 procmail
 3731 ?        00:00:00 procmail <defunct>
 3750 ?        00:00:00 procmail
32634 ?        00:00:00 procmail <defunct>
32661 ?        00:00:00 procmail
 3790 ?        00:00:00 procmail
 3809 ?        00:00:00 procmail
 3822 ?        00:00:00 procmail
 3858 ?        00:00:00 procmail
 3990 ?        00:00:00 procmail <defunct>
 3999 ?        00:00:00 procmail
 4277 ?        00:00:00 procmail <defunct>
 4286 ?        00:00:00 procmail
 4967 ?        00:00:00 procmail <defunct>
 4981 ?        00:00:00 procmail
 5746 ?        00:00:00 procmail <defunct>
 5758 ?        00:00:00 procmail
 8921 ?        00:00:00 procmail
 8930 ?        00:00:00 procmail

and this occures after nearly 2 hours of uptime:

# uptime
 10:12pm  up   1:48,  1 user,  load average: 1.51, 1.59, 1.66

ispconfig is running on suse 9.2 with procmail v3.22

does anybody know if there is a known bug with this software?