Autoindentation fixed and enabled by default.

IPython/frontend/html/notebook/static/js/cell.js

@@ -10,9 +10,10 b' var IPython = (function (IPython) {'
     var Cell = function (notebook) {
         this.notebook = notebook;
         this.selected = false;
-        this.element;
+        this.element = null;
         this.create_element();
-        if (this.element !== undefined) {
+        if (this.element !== null) {
+            this.set_autoindent(true);
             this.element.data("cell", this);
             this.bind_events();
         }

IPython/frontend/html/notebook/static/js/codecell.js

@@ -27,8 +27,6 b' var IPython = (function (IPython) {'
         var input_area = $('<div/>').addClass('input_area box-flex1');
         this.code_mirror = CodeMirror(input_area.get(0), {
             indentUnit : 4,
-            enterMode : 'flat',
-            tabMode: 'shift',
             mode: 'python',
             theme: 'ipython',
             onKeyEvent: $.proxy(this.handle_codemirror_keyevent,this)
@@ -64,7 +62,8 b' var IPython = (function (IPython) {'
                 IPython.notebook.complete_cell(this, line, cur.ch);
                 return true;
             }
-        } else if (event.keyCode === 8) {
+        } else if (event.keyCode === 8 && event.type == 'keydown') {
+            console.log(event);
             // If backspace and the line ends with 4 spaces, remove them.
             var cur = editor.getCursor();
             var line = editor.getLine(cur.line);

IPython/frontend/html/notebook/static/js/textcell.js

@@ -24,8 +24,6 b' var IPython = (function (IPython) {'
         var input_area = $('<div/>').addClass('text_cell_input');
         this.code_mirror = CodeMirror(input_area.get(0), {
             indentUnit : 4,
-            enterMode : 'flat',
-            tabMode: 'shift',
             mode: this.code_mirror_mode,
             theme: 'default',
             value: this.placeholder

IPython/frontend/html/notebook/templates/notebook.html

@@ -121,7 +121,7 b''
                 </div>
                 <div class="section_row">
                     <span id="autoindent_span">
-                        <input type="checkbox" id="autoindent"></input>
+                        <input type="checkbox" id="autoindent" checked="true"></input>
                     </span>
                     <span class="checkbox_label">Autoindent:</span>
                 </div>