ospfd die on his own for no (apparent) reason

We have a number of machines around the globe connected togheter
with a VPN (cipe). To keep track of the routing we use ospfd.
Now we are experiencing strange problems: it seems that ospfd dies
on his own for no apparent reason. We have watchdog cards that
automatically restart ospfd when he is dead, so the problem is not
so 'problematic'. But still is sub-optimal.

I've found nothing on google about such problem.

The only sign in the log files is a message that could point to a
firewall problem, but nowhere it states that such problem should kill
the daemon.

I'm running out of ideas about how to debug this thing. Isn't
continous, sometimes nothing happens for days then suddendly we have
20/25 machines at a time with ospfd dead. Sometimes it dies 10 times
in one hour in the same machine...

Any idea/suggestion?

Davide

--
"Nobody will ever need more than 640k RAM!" -- Bill Gates, 1981
"Windows 95 needs at least 8 MB RAM." -- Bill Gates, 1996
"Nobody will ever need Windows 95." -- logical conclusion