[Zope] zope spins when try to update workflow

[Edmund Moseley]

Hi all,

Not sure if this is the right list or not, please let me know if I 
should redirect my question.
When I try to run "Update security settings" in the portal_workflow 
tool, my zope process gradually swallows up all the cpu, seems to still 
be running fine, but then after a couple of hours, swallows up all the 
memory, the load on the server exceeds 4 and makes it pretty well 
unresponsive.
I have about 35,000 objects in the ZODB.

Has anybody had any similar experience or know of any hints as to how I 
should debug this?

I tried following the guidelines on this website:
http://www.zope.org/Members/4am/debugspinningzope
but couldn't see anything that was actually stuck.

Zope 2.9.5, Python 2.4.4, Plone 2.5.1

Thanks for any advice,
Edmund