Defunct processes

Platform : HP-UX 11.00
DB : Oracle 9.2.0

On one platform I have PMON creating a fair size number (260+ last count) defunct processes. Do not see this behaviour on the other HP-UX/9i platforms.

The PPID points to PMON thus I assume that these children were forked by PMON.

Any ideas as to why these child processes are not being waited upon by PMON? Could this be caused by memory/swap issues? Some users run big/lots of processes exhausting swap and user memory... <sigh>

I recall having problems some years ago on HP-UX with forking children. When a child terminated I did not always get a child died signal.. especially not when two child processes generated this signal at the same time (instead of 2 signals, the parent signal handler only received a single signal). Maybe something similar in this case causing PMON to remain in the dark about its child processes?

Confirmation : these defunct processes do not consume any resources but a process struct in the process list table?

Thanks.

--
Billy