Would be great if you didn't have to open up the popup window to delete task but just had an X on the other side of the list looking button. Ooh or maybe a completed button would be better?
If there was a place called Completed Tasks that could hold all the tasks that you complete but want cleared off of your list.
At the minimum moving the completed tasks down to the bottom of your list would be great....that way the ones that haven't get precedence in your viewing area.
Customer support service by UserEcho