Best way to handle a cancelled task

   So I am still getting used to the new DevForce/Cocktail stuff. One thing that has been happening is that when a user clicks cancel on a dialog the Task throws a task cancelled exception. I read somewhere to handle cancelled tasks with a try/catch. I did that twice and realized that was bad advice. I have too many dialogs and I am not about to litter my code with try/catch blocks. 
I looked at the temphire app and I didn't really see how it was handling the cancel. I am guessing it is in how you implement it. When I implement it this way:
await _DialogManager.ShowDialogAsync(vm.Start(ServiceInstance.ID), DialogButtons.OkCancel);
 I get exceptions. What do I need to change?