[Zope] ZODB caching issue

[David Chandek-Stark]

Setup:
   Zope 2.7.0
   Python 2.3.3
   Linux2
   CMF 1.4.4

Problem Area:
   ZPT which contains a call to a ZPT macro
   The ZPT macro gets data from a parsed RSS feed
   Now using CMFSin 0.6.1
   Previously used RDFSummary 2.4

Symptom:
   When a new item is added to the RSS feed (b/c a news item was 
published), my ZPT displays the RSS data inconsistently with each 
browser refresh -- sometimes the new item appears, sometimes not.

At first I thought this was a problem with the RDFSummary product, but I 
have the same issue with CMFSin. Finally, I at least discovered 
something that "fixes" the problem: flushing the ZODB cache. Obviously, 
I don't want to flush the ZODB cache every time my news feed is updated. 
Is this a known problem that has been resolved in later versions of Zope 
2.7/CMF? Since it's not technically an error, I don't have a traceback.

Thanks for any help,
David