diff --git a/Changelog.yaml b/Changelog.yaml
index 3bbb9e83a1..567f437d53 100644
--- a/Changelog.yaml
+++ b/Changelog.yaml
@@ -23,7 +23,8 @@
   date: 2012-03-23
 
   new features:
-    - title: "E-book viewer: A whole new full screen mode, with no toolbars to distract from the text and the ability to set the width of the column of text via Preferences in the ebook viewer."
+    - title: "E-book viewer: A whole new full screen mode."
+      description: "The new mode has no toolbars to distract from the text and the ability to set the width of the column of text via Preferences in the ebook viewer. Click the Fullscreen button on the toolbar in the viewer to enter fullscreen mode (or press the F11 or Ctrl+Shit+F keys)"
       type: major
       tickets: [959830]
 
diff --git a/src/calibre/ebooks/mobi/debug/headers.py b/src/calibre/ebooks/mobi/debug/headers.py
index 2cc7954559..b367be2e4a 100644
--- a/src/calibre/ebooks/mobi/debug/headers.py
+++ b/src/calibre/ebooks/mobi/debug/headers.py
@@ -328,7 +328,7 @@ class MOBIHeader(object): # {{{
             (self.sect_idx, self.skel_idx, self.datp_idx, self.oth_idx
                     ) = struct.unpack_from(b'>4L', self.raw, 248)
             self.unknown9 = self.raw[264:self.length]
-            if self.meta_orth_indx != self.sect_idx:
+            if self.meta_orth_indx not in {NULL_INDEX, self.sect_idx}:
                 raise ValueError('KF8 header has different Meta orth and '
                         'section indices')