SignalR: Troubleshooting Suggestions for 404 Response at Connection() time - signalr

Question

I am getting a 404 - Not Found Error at connection time in my QA environment. No issue with the same code in our dev integration environment.
I've looked at the other 404's reported here and was not able to find a good match.
Running fiddler, the outgoing request looks very similar in both environments.
Any suggestions on how to troubleshoot this further? Thanks.
* Test Server Connection OK *
var connection = $.connection('http://sdbntrwebdev01.sddev.lpl.com/AlertsService/request/' + token);
POST /AlertsService/request/7077342FE79A4EA99B939C24528EFB8E/negotiate HTTP/1.1
Host: sdbntrwebdev01.sddev.lpl.com
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
X-Requested-With: XMLHttpRequest
Referer: http://sdbntrwebdev01.sddev.lpl.com/alertsservice/healthcheck.aspx
Cookie: ASP.NET_SessionId=zadzj3je5ofm3e51350jl25b; Auth=7077342FE79A4EA99B939C24528EFB8E
Pragma: no-cache
Cache-Control: no-cache
Content-Length: 0
HTTP/1.1 200 OK
Cache-Control: no-cache
Pragma: no-cache
Transfer-Encoding: chunked
Content-Type: application/json; charset=utf-8
Expires: -1
Server: Microsoft-IIS/7.5
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
Date: Tue, 27 Mar 2012 23:51:41 GMT
* QA Server Connection gets 404 *
var connection = $.connection('http://sdalertwebqa01.qadmz.lpl.com/AlertsService/request/' + token);
POST /AlertsService/request/B8E02A155BBF4C55AC4E715C7F1CA968/negotiate HTTP/1.1
Host: sdalertwebqa01.qadmz.lpl.com
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
X-Requested-With: XMLHttpRequest
Referer: http://sdalertwebqa01.qadmz.lpl.com/alertsservice/healthcheck.aspx
Cookie: ASP.NET_SessionId=4zx05otp5oztqjqxvdaafa5e; Auth=B8E02A155BBF4C55AC4E715C7F1CA968
Pragma: no-cache
Cache-Control: no-cache
Content-Length: 0
HTTP/1.1 404 Not Found
Content-Type: text/html
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
Date: Tue, 27 Mar 2012 23:48:12 GMT
Content-Length: 1245

Answer 1

Another guy here found the answer and I will share.
In IIS7, there is a setting called "URLRoutingModule-4.0". The "Edit Managed Module" dialog also contains a checkbox as "Invoke only for requests to ASP.NET applications or managed handlers". Un-check that checkbox.
This setting is at the "Default Web Site" level, double-click "Modules" from feature view to get a list of modules, double-click line item "URLRoutingModule-4.0" to launch the "Edit Managed Module" dialog.