[Zope-dev] How is memory shared between Zope threads?

Hello all, I have noticed incosistencies between Zope threads when objects change. It appears that some threads see the new image of the object while others see the old image. Can anyone enlighten me on how Zope ensures that all threads are seeing the same images? Or at least point me to the modules in the source that handle these matters? Naively, I can think of 2 approaches: a shared memory approach or a separate memory per thread with notifications. Zope behaves like each thread as its own copy of in-memory pieces and sometimes these per/thread memory blocks do not get updated. System info: Zope 2.1.6, Redhat 6.2, PC arch Thanks, Erik