Apache2.nlm called abort() - high util

Hi,

since updating our NW6.5 SP5 servers to eDir 8.7.3.10b we get this on
the logger screen daily (or even twice today):

LibC-9.0-A02: APACHE2.NLM called abort() and will have to be reloaded!
Module APACHE2.NLM is being referenced
You must unload UTILLDAP.NLM before you can unload APACHE2.NLM
(9 more lines of NLMs referencing APACHE2.NLM)

After that, the server goes into a semi-high utilization (one of two
processors goes from 3% to 40% utilization). Operations do seem to be
impacted, but the server does still service everything, it might be
sluggish and/or intermittend, but it's hard to really pin this down. The
only way to get rid of the situation seems to reboot the server.

The apache server services several things: iManager, iPrint and Netstorage.

Any idea what this means or how to get rid of it? I know that SP5 is a
bit out of date, but I don't want to update this box to SP7 yet.

Greetings
Markus Borst