Comment 6 for bug 142667

I did some research and found the way to replicate this bug.
1. Refresh some product
2. Call REQUEST/SESSION (e.g. from PageTemplate)
(Tested with Zope 2.9 and 2.10)

And then I traced the culprit. When refresh is done, old PickleCache for connection is cleared and replaced with a new one. But temp_folder/session_data seems to be broken and some objects stay in the old cache. And when you referece such object again, ne w cache is trying to cache them, and you get:
ValueError: Cache values may only be in one cache.
Tracebacks from previous post are related to session_data attributes.

Anybody knows how to fix this?