HTTP Web Request not corresponding with Response

[johno]

I have a web service written in VB that tries to post to a XML feed
using a HTTP web request.

Occasionally, usually when the server is under load, some of the
responses received do not match the request that was made.

The HTTP keep alive property is set to true, and the provider we are
getting the data from has confirmed that the data we have received is
not the data that they sent in response to the request.

We have increased the worker processes in IIS6.0, which at first
appeared to compound the problem; we have now reduced this to 1 worker
process. Is it possible that serverState was not being maintained that
when the WPs are recycling the requests/responses could become
mis-aligned?

I realise this may not be the right group to post to, but can anyone
help?

Thanks

Johno