Our setup is 

   (Internet) =>  Pound -+- zope1
                         |
                         +- zope2
                         |
                         +- zope3
                         |
                         +- zope4
                         |

The zope instances share a common mysql database.  In the current setup we
do not use ZEO.  Multiple subdomains (xxx.domain.com) are all aliased to
one IP address through the DNS.  Pound acts as a reverse proxy and will,
eventually handle multiple physical instances of the same logical zope.

OS-- RH7.3
Pound-- latest current
Zope 2.6.4
All transactions on port 80 (that is, no SSL)

Under moderate load we occasionally see the delivered response to one
client to be incorrect.  The material delivered comes from a different
part of the our site and is the result of an earlier or a concurrent
request (or so it appears).  The page delivered is incomplete, usually the
first chunk.

My working hypothesis is that this is a Pound problem rather than a zope
problem, but I don't know how to localize it.  The observed problem  
occurs infrequently and, so far, we have not been able to reproduce it.
No Zope error occurs which can be matched up with the observed problem.

Has anyone else seen this Heissenbug?

-d