I have recently upgraded from proxy server 3.6 sp9 to 4.0.9 and have started experiencing some 400 errors within my application. Upon closer examination, the request sent to the proxy server is not what ended up being sent to the web server.
From proxy server logs:
[30/Jun/2009:14:45:12 -0400] "GET /servlet/MenuTree?menuid=Acc_Menu&helpToggle=off&launchpoint=md HTT
P/1.0" - 147 "https://xroads-serv.syniverse.com/AppFrames.html?version=53901" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; InfoPath.1)"
From the Web Server Logs, it appears that all that was sent was 4.0:
[30/Jun/2009:14:45:12 -0400] "4.0" 400 147
This only seems to occur if the clients browser cache settings are set to never check for newer pages, or "automagically" check for newer pages. If set to check for newer pages with every request, everythig appears to work fine. Any suggestions?