diff -r d8339b45edc4 -r b06345320ffb src/js/serializers/ldt_annotate.js
--- a/src/js/serializers/ldt_annotate.js	Tue Sep 01 15:10:17 2015 +0200
+++ b/src/js/serializers/ldt_annotate.js	Tue Sep 01 15:24:26 2015 +0200
@@ -15,6 +15,7 @@
                 title: _data.title,
                 audio: _data.audio
             },
+            id: _data.id ? _data.id : "", // If annotation is new, id will be undefined
             tags: _data.getTagTexts(),
             media: _data.getMedia().id,
             project: _data.project_id,