diff --git a/openlp/core/ui/servicemanager.py b/openlp/core/ui/servicemanager.py
index b18f2f9d8..18b5b6f04 100644
--- a/openlp/core/ui/servicemanager.py
+++ b/openlp/core/ui/servicemanager.py
@@ -975,8 +975,10 @@ class ServiceManager(QtWidgets.QWidget, RegistryBase, Ui_ServiceManager, LogMixi
         prev_item_last_slide = None
         service_iterator = QtWidgets.QTreeWidgetItemIterator(self.service_manager_list)
         while service_iterator.value():
+            # Found the selected/current service item
             if service_iterator.value() == selected:
                 if last_slide and prev_item_last_slide:
+                    # Go to the last slide of the previous service item
                     pos = prev_item.data(0, QtCore.Qt.UserRole)
                     check_expanded = self.service_items[pos - 1]['expanded']
                     self.service_manager_list.setCurrentItem(prev_item_last_slide)
@@ -985,13 +987,17 @@ class ServiceManager(QtWidgets.QWidget, RegistryBase, Ui_ServiceManager, LogMixi
                     self.make_live()
                     self.service_manager_list.setCurrentItem(prev_item)
                 elif prev_item:
+                    # Go to the first slide of the previous service item 
                     self.service_manager_list.setCurrentItem(prev_item)
                     self.make_live()
                 return
+            # Found the previous service item root
             if service_iterator.value().parent() is None:
                 prev_item = service_iterator.value()
+            # Found the last slide of the previous item
             if service_iterator.value().parent() is prev_item:
                 prev_item_last_slide = service_iterator.value()
+            # Go to next item in the tree
             service_iterator += 1
 
     def on_set_item(self, message):
diff --git a/openlp/plugins/presentations/lib/powerpointcontroller.py b/openlp/plugins/presentations/lib/powerpointcontroller.py
index 7645a277a..fd5772e88 100644
--- a/openlp/plugins/presentations/lib/powerpointcontroller.py
+++ b/openlp/plugins/presentations/lib/powerpointcontroller.py
@@ -170,14 +170,17 @@ class PowerpointDocument(PresentationDocument):
         However, for the moment, we want a physical file since it makes life easier elsewhere.
         """
         log.debug('create_thumbnails')
+        generate_thumbs = True
         if self.check_thumbnails():
-            return
+            # No need for thumbnails but we still need the index
+            generate_thumbs = False
         key = 1
         for num in range(self.presentation.Slides.Count):
             if not self.presentation.Slides(num + 1).SlideShowTransition.Hidden:
                 self.index_map[key] = num + 1
-                self.presentation.Slides(num + 1).Export(
-                    str(self.get_thumbnail_folder() / 'slide{key:d}.png'.format(key=key)), 'png', 320, 240)
+                if generate_thumbs:
+                    self.presentation.Slides(num + 1).Export(
+                        str(self.get_thumbnail_folder() / 'slide{key:d}.png'.format(key=key)), 'png', 320, 240)
                 key += 1
         self.slide_count = key - 1