Menus in Drupal can be a little weird. Even with Nice Menus installed, the menu system often seems inflexible, rigid. I have frequently been tempted to create all my own menu items with paths entered manually. But that would be a big mistake. One really important tip is always to let Drupal create a menu item for you (on just about everything that you think you may want to have on a menu one day) and then assign the item to a “holding” parent menu, where it is available but “out of the way”. That way you can always go back and assign it someplace relevant to its function. And, the system will keep up with the path in case it changes, like a view that you change the path on long after its creation.