Is anyone running BorderManager with Trend Micro Interscan VirusWall as a
parent proxy?

I have two independent BM servers that have a Trend Micro Interscan
VirusWall server as an upstream proxy.

If I use either box as my proxy server and try to upload a file e.g.
attach a file to an external mail account (e.g. Gmail), any file over
200Kb in size will fail.

If I set up a PC that has the Trend Micro Virus Wall server as the proxy
uploads are successful.

I have run a packet trace on the BM server and it shows that after a
certain number of transactions the Trend box sens a TCPZeroWindow message
back to the BM server. After this there are several TCPWindowUpdate
messages and then a whole heap of TCPDuplicateACK messages. At this point
the transaction goes down in a screaming heap.

We have tried running this in the middle of the night to see if it was a
load issue and it still failed.

The question I have is anyone out there running this configuration and can
you confirm whether you have seen anything like this issue.