diff --git a/src/calibre/ebooks/metadata/book/__init__.py b/src/calibre/ebooks/metadata/book/__init__.py
index 00bbc68f29..38a824374c 100644
--- a/src/calibre/ebooks/metadata/book/__init__.py
+++ b/src/calibre/ebooks/metadata/book/__init__.py
@@ -131,8 +131,3 @@ SERIALIZABLE_FIELDS =      SOCIAL_METADATA_FIELDS.union(
                            frozenset(['device_collections', 'formats',
                                'cover_data'])
                            # these are rebuilt when needed
-
-# A special set used to optimize the performance of Metadata.__setattr__
-ATTR_NORMAL_FIELDS =    frozenset(STANDARD_METADATA_FIELDS -
-                                     TOP_LEVEL_IDENTIFIERS -
-                                     set('identifiers'))
diff --git a/src/calibre/ebooks/metadata/book/base.py b/src/calibre/ebooks/metadata/book/base.py
index 7aa675c85b..ce80486af8 100644
--- a/src/calibre/ebooks/metadata/book/base.py
+++ b/src/calibre/ebooks/metadata/book/base.py
@@ -9,17 +9,19 @@ import copy, traceback
 
 from calibre import prints
 from calibre.constants import DEBUG
-from calibre.ebooks.metadata.book import SC_COPYABLE_FIELDS
-from calibre.ebooks.metadata.book import SC_FIELDS_COPY_NOT_NULL
-from calibre.ebooks.metadata.book import STANDARD_METADATA_FIELDS
-from calibre.ebooks.metadata.book import TOP_LEVEL_IDENTIFIERS
-from calibre.ebooks.metadata.book import ALL_METADATA_FIELDS
-from calibre.ebooks.metadata.book import ATTR_NORMAL_FIELDS
+from calibre.ebooks.metadata.book import (SC_COPYABLE_FIELDS,
+        SC_FIELDS_COPY_NOT_NULL, STANDARD_METADATA_FIELDS,
+        TOP_LEVEL_IDENTIFIERS, ALL_METADATA_FIELDS)
 from calibre.library.field_metadata import FieldMetadata
 from calibre.utils.date import isoformat, format_date
 from calibre.utils.icu import sort_key
 from calibre.utils.formatter import TemplateFormatter
 
+# Special sets used to optimize the performance of getting and setting
+# attributes on Metadata objects
+SIMPLE_GET = frozenset(STANDARD_METADATA_FIELDS - TOP_LEVEL_IDENTIFIERS)
+SIMPLE_SET = frozenset(SIMPLE_GET - {'identifiers'})
+
 def human_readable(size, precision=2):
     """ Convert a size in bytes into megabytes """
     return ('%.'+str(precision)+'f'+ 'MB') % ((size/(1024.*1024.)),)
@@ -137,7 +139,7 @@ class Metadata(object):
 
     def __getattribute__(self, field):
         _data = object.__getattribute__(self, '_data')
-        if field in ATTR_NORMAL_FIELDS:
+        if field in SIMPLE_GET:
             return _data.get(field, None)
         if field in TOP_LEVEL_IDENTIFIERS:
             return _data.get('identifiers').get(field, None)
@@ -174,7 +176,7 @@ class Metadata(object):
 
     def __setattr__(self, field, val, extra=None):
         _data = object.__getattribute__(self, '_data')
-        if field in ATTR_NORMAL_FIELDS:
+        if field in SIMPLE_SET:
             if val is None:
                 val = copy.copy(NULL_VALUES.get(field, None))
             _data[field] = val
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index a80d21ebdc..bcc4b05399 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -911,7 +911,14 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         Note that the list of formats is not verified.
         '''
         idx = idx if index_is_id else self.id(idx)
-        row = self.data._data[idx]
+        try:
+            row = self.data._data[idx]
+        except:
+            row = None
+
+        if row is None:
+            raise ValueError('No book with id: %d'%idx)
+
         fm = self.FIELD_MAP
         mi = Metadata(None, template_cache=self.formatter_template_cache)
 
@@ -949,14 +956,13 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         mi.book_size   = row[fm['size']]
         mi.ondevice_col= row[fm['ondevice']]
         mi.last_modified = row[fm['last_modified']]
-        id = idx
         formats = row[fm['formats']]
         mi.format_metadata = {}
         if not formats:
             good_formats = None
         else:
             formats = sorted(formats.split(','))
-            mi.format_metadata = FormatMetadata(self, id, formats)
+            mi.format_metadata = FormatMetadata(self, idx, formats)
             good_formats = FormatsList(formats, mi.format_metadata)
         mi.formats = good_formats
         tags = row[fm['tags']]
@@ -969,9 +975,9 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         if mi.series:
             mi.series_index = row[fm['series_index']]
         mi.rating = row[fm['rating']]
-        mi.set_identifiers(self.get_identifiers(id, index_is_id=True))
-        mi.application_id = id
-        mi.id = id
+        mi.set_identifiers(self.get_identifiers(idx, index_is_id=True))
+        mi.application_id = idx
+        mi.id = idx
 
         mi.set_all_user_metadata(self.field_metadata.custom_field_metadata())
         for key, meta in self.field_metadata.custom_iteritems():
@@ -999,12 +1005,12 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
 
         if get_cover:
             if cover_as_data:
-                cdata = self.cover(id, index_is_id=True)
+                cdata = self.cover(idx, index_is_id=True)
                 if cdata:
                     mi.cover_data = ('jpeg', cdata)
             else:
-                mi.cover = self.cover(id, index_is_id=True, as_path=True)
-        mi.has_cover = _('Yes') if self.has_cover(id) else ''
+                mi.cover = self.cover(idx, index_is_id=True, as_path=True)
+        mi.has_cover = _('Yes') if self.has_cover(idx) else ''
         return mi
 
     def has_book(self, mi):