Error 5566 - Infopath form to GetUserProfileByName

Question

I have tried everything I can find to fix this but not having any luck....:(
I have a multi server farm (2 WFE, 2 APP, 1 Load Balancer)
Infopath Form: Created an infopath form that calls the userprofileservice.asmx for method GetUserProfileByName (the data connection is called CreateUserProfileByName in Infopath)
Web Application: Have tried classic and claims with NTLM and Kerberos (nothing works)
Browser : IE 8
The form works fine in Infopath itself. However when published to the server I get the dreaded 5566 error. Pretty much have exhausted all suggestions from the web.
The error message in ULS is - The following query failed: CreateUserProfileByName (User: Domain\MyFirstName.MyLastName, Form Name: Template, IP: , Connection Target: http://spsite/sites/SiteRequest/ConnectionLibrary/file.udcx, Request: http://spsite/sites/SiteRequest/Lists/Requests/AllItems.aspx,
Form ID: urn:schemas-microsoft-com:office:infopath:list:-AutoGen-2012-08-28T23:06:23:223Z Type: DataAdapterException, Exception Message: The remote server returned an error: (401) Unauthorized. The remote server returned an error: (401) Unauthorized.)
Tried using a udcx file with a hard coded username and password
Tried using secure store service
Tried disabling ASP.Net impersonation
Tried with NTLM first and then with Kerberos Web App
Tried both claims and classic authentication ( guess the former does not work with infopath)
Made sure loopback was disabled on all servers
Have ensured I can get to the webservice directly in a browser
Hosts files on the WFEs point to themselves
Nothing works...:(....any ideas?
Thanks in advance,
Jake.

Answer 1

Hi All,
Just an update. Finally after some network tracing I realized this was related to the fact that the request was going through the proxy. Strange thing was that even after disabling the proxy in IE, the system was still routing through the proxy. Then I recalled
a post or two that talked about this in the numerous numerous Internet searches recommendations that I had already attempted. And sure enough that seemed to fix the issue.
 <system.net>
   <defaultProxy>
     <proxy autoDetect="false" />
   </defaultProxy>
</system.net>
Needless to say, the edit should be done through a feature. Anyway, hope this helps someone else also.
Thanks,
Jake.