Commented Unassigned: Error registering task on Windows Vista [12469]

On Windows Vista, I can't register a task when a password is required. I'm using the version 2.5.27 of the wrapper.
The next code works on other operative systems, but not in Windows Vista:

TaskDefinition td = taskScheduler.NewTask();
td.Actions.Add(Application.ExecutablePath, string.Format("\"{0}\"", configPath));
td.Settings.DisallowStartIfOnBatteries = false;
td.Settings.StopIfGoingOnBatteries = false;

Task task = taskScheduler.RootFolder.RegisterTaskDefinition(taskName, td);
task.Definition.Principal.LogonType = TaskLogonType.Password;
task.Definition.Principal.RunLevel = TaskRunLevel.Highest;

TaskEditDialog editorForm = new TaskEditDialog(task, true, true);
editorForm.ShowDialog();

When clicking on OK button of the Task Edit Dialog, we are prompted to type password of the account. Even if the password is right, we get the error of the screenshot.
Comments: ** Comment from web user: dahall **

My guess, given that other programs work, is that there is something tied to UAC for your program unique to that system. Have you tested this on multiple Windows 7 machines? If it is just this one, then check those permissions. If multiple, then check your program's manifest. I can tell you that multiple Windows 7 and Vista installations are working with the latest bits.