[Zope] ZODB size limitations?

[nwingfield at che-llp.com]

In an effort to put our Zope-based system into production, I ran an import
script to pull in historical data external to Zope.  At this point we are
experiencing some very strange behaviors - seemingly related to traversal
of the object tree - that did not occur prior to the import.  At this point
we have close to 150,000 objects, each containing a handful of metadata and
nothing more.  A large number of these are folderish.  I expect this
database to grow much larger in a very short time, providing it does not
die a premature death.  Our file system is Reiser FS and our ZODB is
running on DirectoryStorage, rather than the Data.fs file.  I worry that
we're pushing Zope beyond its capabilities with this number of objects, but
I don't really know.  Does anyone have experience with databases of this
size?  Any ideas on limitations to number of objects the ZODB can
comfortably manage, or the size to which the ZODB can comfortably grow?