diff --git a/resources/default_tweaks.py b/resources/default_tweaks.py
index efcd004acd..efa46fa7ae 100644
--- a/resources/default_tweaks.py
+++ b/resources/default_tweaks.py
@@ -143,7 +143,7 @@ auto_connect_to_folder = ''
 # documentation, 'Darkover' is called the value and 'My Series' is called the
 # category. If two books have fields that generate the same collection name,
 # then both books will be in that collection.
-# This set of tweaks tweak lets you specify for a standard or custom field how
+# This set of tweaks lets you specify for a standard or custom field how
 # the collections are to be named. You can use it to add a description to a
 # standard field, for example 'Foo (Tag)' instead of the 'Foo'. You can also use
 # it to force multiple fields to end up in the same collection. For example, you
@@ -288,4 +288,4 @@ locale_for_sorting =  ''
 # Set whether to use one or two columns for custom metadata when editing
 # metadata  one book at a time. If True, then the fields are laid out using two
 # columns. If False, one column is used.
-metadata_single_use_2_cols_for_custom_fields = True
\ No newline at end of file
+metadata_single_use_2_cols_for_custom_fields = True
diff --git a/src/calibre/ebooks/mobi/mobiml.py b/src/calibre/ebooks/mobi/mobiml.py
index 001cf2c1e9..9733c5f4ca 100644
--- a/src/calibre/ebooks/mobi/mobiml.py
+++ b/src/calibre/ebooks/mobi/mobiml.py
@@ -468,8 +468,9 @@ class MobiMLizer(object):
                         vtag.append(child)
                     else:
                         break
-                for child in vbstate.para:
-                    vtag.append(child)
+                if vbstate.para is not None:
+                    for child in vbstate.para:
+                        vtag.append(child)
                 return
 
         if text or tag in CONTENT_TAGS or tag in NESTABLE_TAGS: