WP 3.5.1, version 6.4.2, and I got the following error when I tried to add other user roles to see the dashboard widget:
Warning: stripslashes() expects parameter 1 to be string, array given in ..../wp-includes/kses.php on line 1257
It won't save, and it also unchecks all checkboxes, including the ones under not to track. None of my choices are saved.
I went back to 6.4.1 and it is now displaying the dashboard widget again and saving checkbox choices.