DotNetOpenAuth LinkedIn post share error using Asp.Net MVC - oauth

Question

DotNetOpenAuth is an amazing package. However, I keep hitting some hurdle or other. Till now most of them got solved, now I have hit a problem, which is taking up a lot of my time.
The Problem:
I want to share a post on linkedin using DotNetOpenAuth. I was able to share a few posts a while back, but all of a sudden things are now broken, and I am not able to post shares anymore. I do not recollect making much changes in my code. Can someone have a look at my diagnosis, code and see if I am messing something up?
The Diagnosis:
I ran fiddler while making requests via my code and via LinkedIn's Rest Console. Here's the Fiddler output for both scenarios:
Fiddler Output for request that was made via Rest Console provided by linkedin
POST /v1/people/~/shares HTTP/1.1
Authorization: OAuth oauth_consumer_key="{consumer_key}",oauth_signature_method="HMAC-SHA1",oauth_timestamp="1362258084",oauth_nonce="-141812272",oauth_version="1.0",oauth_token="{access_token}",oauth_signature="HBMUfvHYJAxz%2BszxStVJ%2BhfQPEQ%3D"
Host: api.linkedin.com
Content-Length: 645
X-Target-URI: http://api.linkedin.com
Content-Type: application/xml
Connection: Keep-Alive
<?xml version="1.0" encoding="UTF-8"?>
<share>
<comment>test comment</comment>
<content>
<title>test title</title>
<submitted-url>{my_test_url}</submitted-url>
<submitted-image-url>{my_image_url}</submitted-image-url>
</content>
<visibility>
<code>anyone</code>
</visibility>
</share>
Fiddler output for request that was made via my code(using DNOA):
POST http://api.linkedin.com/v1/people/~/shares HTTP/1.1
Authorization: OAuth oauth_token="{access_token}",oauth_consumer_key="{my_consumer_key}",oauth_nonce="ECYFLc0l",oauth_signature_method="HMAC-SHA1",oauth_signature="FobR745YkMlmBpOqoTDr8CwGZIQ%3D",oauth_version="1.0",oauth_timestamp="1362263560"
Content-Type: application/xml
Host: api.linkedin.com
Content-Length: 510
Connection: Keep-Alive
<?xml version="1.0" encoding="UTF-8"?>
<share>
<comment>test comment</comment>
<content>
<title>test title</title>
<description>test description</description>
<submitted-url>{my_test_url}</submitted-url>
<submitted-image-url>{my_image_url}</submitted-image-url>
</content>
<visibility>
<code>anyone</code>
</visibility>
</share>
More details:
I know that I need to pass scope while performing oauth authentication, so already have this in place. I also get proper permission prompt that reads "NETWORK UPDATES Retrieve and post updates to LinkedIn as you" when user is authorizing my application
Do note that I do get an access token, and I am able to perform some read operations, like for getting user details using this token, however, I am not able to use the token to share posts on LinkedIn. Currently the implementation is using LinkedIn oAuth 1.0a.
Here's my code block as well:
public bool PostToLinkedIn(WebConsumer consumer, string sShareMessageXml, string accessToken = null)
{
var payload = Encoding.ASCII.GetBytes(sShareMessageXml);
AuthorizedTokenResponse token = null;
bool bIsAccessTokenSupplied = !string.IsNullOrEmpty(accessToken);
if (!bIsAccessTokenSupplied)
{
token = consumer.ProcessUserAuthorization();
}
if (token != null || bIsAccessTokenSupplied)
{
this.AccessToken = bIsAccessTokenSupplied ? accessToken : token.AccessToken;
var resourceEndpoint = new MessageReceivingEndpoint("http://api.linkedin.com/v1/people/~/shares", HttpDeliveryMethods.PostRequest | HttpDeliveryMethods.AuthorizationHeaderRequest);
HttpWebRequest request = consumer.PrepareAuthorizedRequest(resourceEndpoint, AccessToken);
request.ServicePoint.Expect100Continue = false;
request.Method = "POST";
request.ContentLength = payload.Length;
request.ContentType = "application/xml";
using (Stream requestStream = request.GetRequestStream())
{
requestStream.Write(payload, 0, payload.Length);
}
var response = consumer.Channel.WebRequestHandler.GetResponse(request);
var responseData = response.GetResponseReader().ReadToEnd();
var xmlData = XDocument.Parse(responseData);
if (xmlData.Elements(XName.Get("update")).Any())
{
return true;
}
}
return false;
}
Please let me know if you need more details. Any help would be great.
I have posted a brief version of the same problem on DNOA's google group as well here. Hopefully someone has faced this issue and has a solution.