PhoneCallTask fails - windows-phone-7

Question

This is a really simple task but somehow it fails...
private void TextBlock_Tap_1(object sender, System.Windows.Input.GestureEventArgs e)
{
if (WasSwipe != true)
{
//JUST TO CHECK THAT CODE GETS HERE - RUNS PERFECT
MessageBox.Show("");
//FUNCTION
var phoneCallTask = new PhoneCallTask
{
DisplayName = "Kunal Chowdhury",
PhoneNumber = "0208795446322"
};
phoneCallTask.Show();
//FAILS HERE, AFTER SHOW
}
else
{
WasSwipe = false;
}
}
When i want to show task it fails with this:
Message: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))
Source: Microsoft.Phone
Stack-trace: at Microsoft.Phone.Tasks.PhoneCallTask.NativeMethods.PhoneInitiateOutgoingPhoneCall_External(String
pDialString, String pDisplayName)
at Microsoft.Phone.Tasks.PhoneCallTask.PhoneDial(Object
phoneCallTask)
at
System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object
state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext
executionContext, ContextCallback callback, Object state, Boolean
preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext
executionContext, ContextCallback callback, Object state, Boolean
preserveSyncCtx)
at
System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
IN ADDITION:
Email task works:
EmailComposeTask emailComposeTask = new EmailComposeTask();
emailComposeTask.Subject = "message subject";
emailComposeTask.Body = "message body";
emailComposeTask.To = "recipient#example.com";
emailComposeTask.Cc = "cc#example.com";
emailComposeTask.Bcc = "bcc#example.com";
emailComposeTask.Show();

Answer 1

You probably didn't specify following permission in your app manifest file:
ID_CAP_PHONEDIALER