diff --git a/oml/meta/google.py b/oml/meta/google.py
index 6c9b477..6c7ff4a 100644
--- a/oml/meta/google.py
+++ b/oml/meta/google.py
@@ -52,7 +52,7 @@ def info(key, value):
         api_limit.error = True
         raise IOError(url, r)
     if not 'items' in r:
-        print('unknown %s: %s [%s]' % (key, value, r))
+        logger.debug('unknown %s: %s [%s]', key, value, r)
         return {}
     _data = r['items'][0]['volumeInfo']
     _id = r['items'][0]['id']
@@ -91,7 +91,7 @@ def info(key, value):
                     data['isbn'] = []
                 data['isbn'].append(k['identifier'])
             else:
-                print('unknown identifier', k)
+                logger.debug('unknown identifier %s', k)
         if 'isbn' in data:
             data['isbn'] = [to_isbn13(i) for i in data['isbn']][0]
 
diff --git a/oml/nodes.py b/oml/nodes.py
index d4d1dfd..4abf068 100644
--- a/oml/nodes.py
+++ b/oml/nodes.py
@@ -262,7 +262,11 @@ class Node(Thread):
                 return False
             if not changes:
                 return False
-            r = Changelog.apply_changes(u, changes, first=from_revision == 0)
+            try:
+                r = Changelog.apply_changes(u, changes, first=from_revision == 0)
+            except:
+                logger.debug('apply_changes failed', exc_info=True)
+                r = False
             return r
 
     def peering(self, action):