Set cursor pos in edit mode before attempting to jump cells.

IPython/html/tests/notebook/dualmode_arrows.js

@@ -37,14 +37,14 @@ casper.notebook_test(function () {
         this.validate_notebook_state('click cell 3', 'edit', 3);
         this.trigger_keydown('down');
         this.validate_notebook_state('down at end of notebook', 'edit', 3);
-        // cursor
+        this.set_cell_editor_cursor(3, 0, 0);
         this.trigger_keydown('up');
         this.validate_notebook_state('up', 'edit', 2);
         this.click_cell_editor(0);
         this.validate_notebook_state('click 0', 'edit', 0);
         this.trigger_keydown('up');
         this.validate_notebook_state('up at top of notebook', 'edit', 0);
-        // cursor
+        this.set_cell_editor_cursor(0, 0, 10);
         this.trigger_keydown('down');
         this.validate_notebook_state('down', 'edit', 1);
     });