diff --git a/src/calibre/customize/__init__.py b/src/calibre/customize/__init__.py
index 6466d198a0..68d94bf178 100644
--- a/src/calibre/customize/__init__.py
+++ b/src/calibre/customize/__init__.py
@@ -255,12 +255,14 @@ class CatalogPlugin(Plugin):
 
     def search_sort_db(self, db, opts):
 
+        '''
         # Don't add Catalogs to the generated Catalogs
         cat = _('Catalog')
         if opts.search_text:
             opts.search_text += ' not tag:'+cat
         else:
             opts.search_text = 'not tag:'+cat
+        '''
 
         db.search(opts.search_text)
 
diff --git a/src/calibre/gui2/catalog/catalog_epub_mobi.py b/src/calibre/gui2/catalog/catalog_epub_mobi.py
index 841ba5f6ad..4bc4d60e5c 100644
--- a/src/calibre/gui2/catalog/catalog_epub_mobi.py
+++ b/src/calibre/gui2/catalog/catalog_epub_mobi.py
@@ -17,7 +17,7 @@ class PluginWidget(QWidget,Ui_Form):
     TITLE = _('E-book Options')
     HELP  = _('Options specific to')+' EPUB/MOBI '+_('output')
     OPTION_FIELDS = [('exclude_genre','\[[\w ]*\]'),
-                     ('exclude_tags','~'),
+                     ('exclude_tags','~,'+_('Catalog')),
                      ('read_tag','+'),
                      ('note_tag','*')]
 
diff --git a/src/calibre/library/catalog.py b/src/calibre/library/catalog.py
index b2e6fa0efc..fd9c36da02 100644
--- a/src/calibre/library/catalog.py
+++ b/src/calibre/library/catalog.py
@@ -247,7 +247,7 @@ class EPUB_MOBI(CatalogPlugin):
                           help=_("Regex describing tags to exclude as genres.\n" "Default: '%default' excludes bracketed tags, e.g. '[<tag>]'\n"
                           "Applies to: ePub, MOBI output formats")),
                    Option('--exclude-tags',
-                          default='~',
+                          default=('~,'+_('Catalog')),
                           dest='exclude_tags',
                           help=_("Comma-separated list of tag words indicating book should be excluded from output.  Case-insensitive.\n"
                           "--exclude-tags=skip will match 'skip this book' and 'Skip will like this'.\n"
@@ -758,7 +758,10 @@ class EPUB_MOBI(CatalogPlugin):
             if self.opts.ids:
                 self.opts.search_text = search_phrase
             else:
-                self.opts.search_text = self.opts.search_text + " " + search_phrase
+                if self.opts.search_text:
+                    self.opts.search_text += " " + search_phrase
+                else:
+                    self.opts.search_text = search_phrase
 
             # Fetch the database as a dictionary
             data = self.plugin.search_sort_db(self.db, self.opts)
@@ -2495,6 +2498,7 @@ class EPUB_MOBI(CatalogPlugin):
                     pw.MagickThumbnailImage(thumb, 75, 100)
                     pw.MagickWriteImage(thumb, os.path.join(image_dir, thumb_file))
                     pw.DestroyMagickWand(thumb)
+                    pw.DestroyMagickWand(img)
                 except IOError:
                     print "generate_thumbnail() IOError with %s" % title['title']
                 except RuntimeError: