In my application I use the WebBrowser control.
Since the content requires a higher version of IE - I used the FEATURE_BROWSER_EMULATION as explained here: http://msdn.microsoft.com/en-us/library/ee330730(v=vs.85).aspx
this worked perfectly until I needed to include some parameters as POST, so I used the following overload of the 'Navigate' method:
Navigate(string urlString, string targetFrameName, byte[] postData, string additionalHeaders)
But since I started using this new overload, the WebBrowser's emulation stopped working.
I used SysInternals' Process-Monitor and it is clearly visible that when using POST parameters - the FEATURE_BROWSER_EMULATION key is not accessed.