SharePoint 2010 - SSRS 2010 ReportingService2010.CreateSubscription Error: User cannot be found.

Not sure if this is the right place for my question\issue but here goes.

Have a Sharepoint 2010 installation with SQL 2008 R2 reporting services in integrated mode. I havea  webpart that copies a template site and its rpeorts, then fixes the reports for the new site (rs.ListChildren) I then need to create some subscriptions on those reports, but I am getting the following error:

FAILED:
<errorcode xmlns="http://www.microsoft.com/sql/reportingservices">rsDeliveryError</errorcode><httpstatus xmlns="http://www.microsoft.com/sql/reportingservices">400</httpstatus><message xmlns="http://www.microsoft.com/sql/reportingservices">A subscription delivery
error has occurred.</message><helplink xmlns="http://www.microsoft.com/sql/reportingservices">http://go.microsoft.com/fwlink/?LinkId=20476&EvtSrc=Microsoft.ReportingServices.Diagnostics.Utilities.ErrorStrings&EvtID=rsDeliveryError&ProdName=Microsoft%20SQL%20Server%20Reporting%20Services&ProdVer=10.50.2500.0</helplink><productname xmlns="http://www.microsoft.com/sql/reportingservices">Microsoft SQL Server
Reporting Services</productname><productversion xmlns="http://www.microsoft.com/sql/reportingservices">10.50.2500.0</productversion><productlocaleid xmlns="http://www.microsoft.com/sql/reportingservices">1033</productlocaleid><operatingsystem xmlns="http://www.microsoft.com/sql/reportingservices">OsIndependent</operatingsystem><countrylocaleid xmlns="http://www.microsoft.com/sql/reportingservices">1033</countrylocaleid><moreinformation xmlns="http://www.microsoft.com/sql/reportingservices">ReportingServicesLibrary<message msrs:ErrorCode="rsDeliveryError" msrs:HelpLink="http://go.microsoft.com/fwlink/?LinkId=20476&EvtSrc=Microsoft.ReportingServices.Diagnostics.Utilities.ErrorStrings&EvtID=rsDeliveryError&ProdName=Microsoft%20SQL%20Server%20Reporting%20Services&ProdVer=10.50.2500.0" xmlns:msrs="http://www.microsoft.com/sql/reportingservices">A subscription delivery error has
occurred.</message><moreinformation>Microsoft.SharePoint<message>User
cannot be found.</message></moreinformation></moreinformation><warnings xmlns="http://www.microsoft.com/sql/reportingservices"></warnings>

If I am able to a rs.ListSubscriptions on another site and retrieve subscription settings but if I try to create a subscription this is what I am getting.

Any ideas?

Oh BTW I am able to create DataSources following the same process, sucessfully.

using System;
using Microsoft.SharePoint;
using Microsoft.SqlServer.ReportingServices2010;
using System.Net;
using System.Web;
using System.Text;
using System.IO;
using System.Collections.Generic;
using System.Diagnostics;
using System.Web.Services;
using System.Web.Services.Protocols;

namespace TPG.ProjectInit
{
    class Sample_Subscription
    {
        private void SetupSubscriptions()
        {
            SPSecurity.RunWithElevatedPrivileges(delegate
            {
                using (SPSite siteColl = new SPSite(SPContext.Current.Site.ID))
                {
                    using (SPWeb web = siteColl.OpenWeb("MySite/Reports"))
                    {
                        if (web.Exists)
                        {
                            String shortSiteURL = String.Empty;
                            web.AllowUnsafeUpdates = true;

                            try
                            {

                                ReportingService2010 reportingWS = new ReportingService2010();
                                reportingWS.Credentials = CredentialCache.DefaultCredentials;

                                string report;

                                ExtensionSettings extSettings;
                                string desc;
                                string eventType;
                                string scheduleXml;
                                string matchData;
                                DateTime startDateTime = DateTime.UtcNow;
                                ParameterValue[] extensionParams = null;

                                #region sample subscription

                                ReportingService2010 rs = new ReportingService2010();
                                rs.Credentials = System.Net.CredentialCache.DefaultCredentials;

                                report = "http://MyServer/MySite/Reports/Sales Order Detail.rdl";

                                desc = "Send to Document Library";
                                eventType = "TimedSubscription";
                                scheduleXml =
                                   @"<ScheduleDefinition>" +
                                    "   <StartDateTime>2003-02-24T09:00:00-08:00" +
                                    "   </StartDateTime>" +
                                    "   <WeeklyRecurrence>" +
                                    "      <WeeksInterval>1</WeeksInterval>" +
                                    "      <DaysOfWeek>" +
                                    "         <Monday>True</Monday>" +
                                    "      </DaysOfWeek>" +
                                    "   </WeeklyRecurrence>" +
                                    "</ScheduleDefinition>";

                                extensionParams = new ParameterValue[6];

                                extensionParams[0] = new ParameterValue();
                                extensionParams[0].Name = "RENDER_FORMAT";
                                extensionParams[0].Value = "EXCEL";

                                extensionParams[1] = new ParameterValue();
                                extensionParams[1].Name = "FILENAME";
                                extensionParams[1].Value = "Sales Order Detail";

                                extensionParams[2] = new ParameterValue();
                                extensionParams[2].Name = "FILEEXTN";
                                extensionParams[2].Value = "True";

                                extensionParams[3] = new ParameterValue();
                                extensionParams[3].Name = "PATH";
                                extensionParams[3].Value = "http://MyServer/MySite/Reports/";


                                extensionParams[4] = new ParameterValue();
                                extensionParams[4].Name = "WRITEMODE";
                                extensionParams[4].Value = "Overwrite";

                                extensionParams[5] = new ParameterValue();
                                extensionParams[5].Name = "AUTOCOPY";
                                extensionParams[5].Value = "False";

                                matchData = scheduleXml;
                                extSettings = new ExtensionSettings();
                                extSettings.ParameterValues = extensionParams;
                                extSettings.Extension = "Report Server DocumentLibrary";

                                try
                                {
                                    rs.CreateSubscription(report, extSettings, desc,
                                        eventType, matchData, null);
                                }

                                catch (SoapException e)
                                {
                                    Debug.WriteLine(e.Detail.InnerXml.ToString());
                                }


                                #endregion //sample subscription

                            }
                            catch (Exception ex)
                            {
                                Debug.WriteLine("FAILED: " + ex.Message);
                                return;
                            }
                        }
                        else
                        {
                            Debug.WriteLine("FAILED: Site does not exist");
                            return;
                        }
                    }
                }
            });
        }
    }
}