C# XSLT problem, parameter passing in not working

public string Transform(string xslt,
                                string xmlBuffer,
                                string xsltParamsAsXml, 
                                string namespaceXML)
        {
            string functionReturnValue = null;

            try
            {

            XmlDocument xmlParamsDoc = new XmlDocument();

            xmlParamsDoc.LoadXml(xsltParamsAsXml);
            
            XsltArgumentList argsList = new XsltArgumentList(); 
            
            foreach (XmlNode xmlParam in xmlParamsDoc.SelectNodes("/Params/Param"))
            {
                string name = xmlParam.Attributes.GetNamedItem("name").InnerText;
                string value = xmlParam.Attributes.GetNamedItem("value").InnerText;
                argsList.AddParam(name, namespaceXML, value);
            }

                XmlDocument XMLDOM = new XmlDocument();
                
                XMLDOM.LoadXml(xmlBuffer);

                //' We create a new XslCompiledTransform object which supercedes the XslTransform class 
                XslCompiledTransform Transformer = new XslCompiledTransform();

                //XmlReader xmlReader = new XmlTextReader();

                //Convert to Bytes
                System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
                Byte[] bytes = encoding.GetBytes(xslt);

                MemoryStream ms = new MemoryStream(bytes);
                Stream xlstStream = (Stream)ms;

                XmlReader xmlReader = XmlReader.Create(xlstStream);

                //' We have to load the XSL style sheet before we perform any transformation 
                Transformer.Load(xmlReader);

                //' We are setting the XmlWriterSettings so that we match the conformance level of the XmlReaderSettings 
                XmlWriterSettings myWriterSettings = new XmlWriterSettings();
                myWriterSettings.ConformanceLevel = ConformanceLevel.Fragment;

                //' Create a string builder which will eventually contain our transformed results 

                StringBuilder myString = new StringBuilder();
                //' Perform the transformation using the XmlDocument, the Parameters created from the Iterator and 
                //' write it to the StringBuilder 

                Transformer.Transform(XMLDOM, argsList, XmlWriter.Create(myString, myWriterSettings));

                functionReturnValue = myString.ToString();

            } /* throw */
            catch (Exception ex)
            {
                GenericLogger.ErrorLog(_userName, _machineName, ex.Message);

                throw new Exception("xmlFunctions:: Transform " + ex.Message);
            } /* catch */

            return functionReturnValue; 

        }

fileXLST = @"\\server2\batchXSLTDatabasesForRuleEngine.xslt";
xlstBuf = uF.ReadFileToString(fileXLST);
string ParamXML = "<Params><Param name='Environment' value='DEV'></Param></Params>";
xmlBuf = uF.ReadFileToString(@"\\SERVER2\XML\AlphaStartup02.xml");
string xmlTransformedDB = xlst.Transform(xlstBuf, xmlBuf, ParamXML, "");
xmlTransformedDB = xlst.FormatXml(xmlTransformedDB);