New Post: Weird exception

I have just tried to run the example from my asp.net application. Connections in task service are working:

using (TaskService ts = new TaskService())
            {
                // Create a new task definition and assign properties
                TaskDefinition td = ts.NewTask();
                td.RegistrationInfo.Description = "Does something";
                td.Principal.LogonType = TaskLogonType.InteractiveToken;

                // Add a trigger that will fire the task at this time every other day
                DailyTrigger dt = (DailyTrigger)td.Triggers.Add(new DailyTrigger { DaysInterval = 2 });
                dt.Repetition.Duration = TimeSpan.FromHours(4);
                dt.Repetition.Interval = TimeSpan.FromHours(1);

                // Add a trigger that will fire every week on Friday
                td.Triggers.Add(new WeeklyTrigger
                {
                    StartBoundary = DateTime.Today + TimeSpan.FromHours(2),
                    DaysOfWeek = DaysOfTheWeek.Friday
                });

                // Add an action that will launch Notepad whenever the trigger fires
                td.Actions.Add(new ExecAction("cmd.exe", "c:\\test.log", null));

                // Register the task in the root folder
                const string taskName = "Test";
                ts.RootFolder.RegisterTaskDefinition(taskName, td);

                // Retrieve the task, change the trigger and re-register it
                Task t = ts.GetTask(taskName);
                td = t.Definition;
                td.Triggers[0].StartBoundary = DateTime.Today + TimeSpan.FromDays(7);
                ts.RootFolder.RegisterTaskDefinition(taskName, td);

            }

And in the last row strange exception has appeared:
System.Runtime.InteropServices.COMException: (57,4):Task:

Please, help!