public static string GetUa(HttpRequest hr)
    {
        try
        {
            string visitorBrowser = hr.UserAgent.ToString();
            string originalBrowser = hr.ServerVariables["X-OperaMini-Phone-UA"];
            string anotherOriginalBrowser = hr.ServerVariables["X-Device-User-Agent"]; //novarra
            
            if (!String.IsNullOrEmpty(originalBrowser))
            {
                return "OPERAMINI " + originalBrowser;
            }
            else
            {
                if (!String.IsNullOrEmpty(anotherOriginalBrowser))
                {
                    return "NOVARRA " + anotherOriginalBrowser;
                }
                else
                {
                    return visitorBrowser;
                }
            }
        }
        catch
        {
            return "No UA Found";
        }
    }

Nokia acquired transcoding company Novarra!

"Novarra, the Internet Mobility company, provides high performance mobile internet browsers and platforms for operators, handset manufacturers and internet brands to create new services and revenue streams for smartphones, features phones and mobile broadband devices.  The solutions deliver a high quality mobile user experience for services including full rich web browsing, search, widgets, apps, video and advertising. Global, commercial deployments over eight years have proven consumer satisfaction, uptake and increased data service revenues" 

Novarra is the biggest transcoding company out there. It basically renders web pages and makes them suitable for non smart mobile phones. While doing that it does not obey transcoding specifications and hides phone capabilities, it also renders mobile web pages. Regardless your site designed for mobile phones or not it renders mobile web pages same way and usually inserts different content on top and bottom of pages. It simply hijacks your site and uses for it's own benefit.

I hope Nokia will sort Novarra out!