[Zope] BTreeFolder2 add speed with 10k objects

[Jeff Youel]

I'm using a CMFBTreeFolder to hold objects for a query later.  Each
object in the 
folder has a few string members.  The folder now has about 10,200
objects.  When
I add a new instance of the object to the folder, it takes around 18
seconds.  
I've tracked the hotspot down to BTreeFolder2._setOb()'s:

	tree[id] = object

which takes around 17 seconds.  By comparison, the rest of the request 
including cataloging the object takes less than a second.

I'm using Zope 2.6.1, CMF 1.3.1.  I updated by BTreeFolder2 code to the
latest 
from CVS and ran manage_cleanup() which reported no errors.  Any ideas
how I can
improve this?

Thanks,
Jeff