Eric,
This appears to be by design and is related to the negotiation protocol that is used with intgrated authentication. If you monitor the sequence from the client side, you will see an initial request by the client with an Authorization: Negotiage header. This elicits a 401 response by the server and includes a WWW-Authenticate: Negotiate header. The client then responds with a Authorization: Negotiate header containing base64 encrypted credentials. The server should then accept these and return a 200 status with the requested data. The client specifies Connection: Keep-Alive in each header to ensure the conversation proceeds correctly. Once authenticated, the client seems to be able to reuse the connection for short periods, hence the blocks of 200s interspersed with 401s.
There are lots of articles on the web that describe the negotiate protocol better than I have. Hope this helps.
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