You should be able to control each layout exactly the way you want regarding percussion views. This amount of control means that even if you set the percussion kit for single line when you created it, you would still need to set it for single line in whatever layout you are using. When you bring up Layout Options, make sure you have the correct layout selected. Then under Players, set the Percussion to Single-line Instruments and you should be good to go. (Mine defaults to Grid view, so I need to change it as well). Before closing the Layout Options dialog, make sure you push the Apply button. (Forgetting to push the “Apply” button has happened to me when I am in a hurry and get “close-the-dialog-quickly-syndrome” 
