diff --git a/src/calibre/ebooks/metadata/__init__.py b/src/calibre/ebooks/metadata/__init__.py
index f087f861ba..02401b25e6 100644
--- a/src/calibre/ebooks/metadata/__init__.py
+++ b/src/calibre/ebooks/metadata/__init__.py
@@ -55,7 +55,9 @@ except:
 
 _ignore_starts = u'\'"'+u''.join(unichr(x) for x in range(0x2018, 0x201e)+[0x2032, 0x2033])
 
-def title_sort(title, order=tweaks['title_series_sorting']):
+def title_sort(title, order=None):
+    if order is None:
+        order = tweaks['title_series_sorting']
     title = title.strip()
     if order == 'strictly_alphabetic':
         return title
diff --git a/src/calibre/gui2/library/models.py b/src/calibre/gui2/library/models.py
index 0d70fbc610..9da9a2f538 100644
--- a/src/calibre/gui2/library/models.py
+++ b/src/calibre/gui2/library/models.py
@@ -23,7 +23,6 @@ from calibre.ebooks.metadata.meta import set_metadata as _set_metadata
 from calibre.utils.search_query_parser import SearchQueryParser
 from calibre.library.caches import _match, CONTAINS_MATCH, EQUALS_MATCH, \
     REGEXP_MATCH, MetadataBackup
-from calibre.library.cli import parse_series_string
 from calibre import strftime, isbytestring, prepare_string_for_xml
 from calibre.constants import filesystem_encoding, DEBUG
 from calibre.gui2.library import DEFAULT_SORT
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index eb72c1b407..c50d1669e5 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -2133,12 +2133,12 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                 self.conn.execute('DELETE FROM tags WHERE id=?', (id,))
                 self.conn.commit()
 
-    series_index_pat = re.compile(r'(.*)\[([.0-9]+)\]')
+    series_index_pat = re.compile(r'(.*)\s+\[([.0-9]+)\]$')
 
     def _get_series_values(self, val):
         if not val:
             return (val, None)
-        match = self.series_index_pat.match(val)
+        match = self.series_index_pat.match(val.strip())
         if match is not None:
             idx = match.group(2)
             try:
diff --git a/src/calibre/library/sqlite.py b/src/calibre/library/sqlite.py
index 521c275efe..0458ada27b 100644
--- a/src/calibre/library/sqlite.py
+++ b/src/calibre/library/sqlite.py
@@ -16,7 +16,6 @@ from datetime import datetime
 from functools import partial
 
 from calibre.ebooks.metadata import title_sort, author_to_author_sort
-from calibre.utils.config import tweaks
 from calibre.utils.date import parse_date, isoformat
 from calibre import isbytestring, force_unicode
 from calibre.constants import iswindows, DEBUG