c# – TransactionScope中的Membership.GetUser()抛出Transactio

using ( TransactionScope transactionScope = new TransactionScope() )
    {
        try
        {
            using ( MyDataContext context = new MyDataContext() )
            {
                Guid accountID = new Guid( Request.QueryString[ "aid" ] );
                Account account = ( from a in context.Accounts where a.UniqueID.Equals( accountID ) select a ).SingleOrDefault();
                IQueryable < My_Data_Access_Layer.Login > loginList = from l in context.Logins where l.AccountID == account.AccountID select l;

                foreach ( My_Data_Access_Layer.Login login in loginList )
                {
                    MembershipUser membershipUser = Membership.GetUser( login.UniqueID );
                }

                [... lots of DeleteAllOnSubmit() calls]

                context.SubmitChanges();
                transactionScope.Complete();
            }   
        }

        catch ( Exception E )
        {
        [... reports the exception ...]
        }
    }

在调用Membership.GetUser()时发生错误.

我的连接字符串是：

<add name="MyConnectionString" connectionString="Data Source=localhostSQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=True"
   providerName="System.Data.SqlClient" />

我read的一切都告诉我,TransactionScope应该神奇地应用于会员电话.用户存在(否则我希望返回null.)