OK, so the codec was working - and I was thinking it was my fault :(

SVN revision: 15071

src/bin/e_ipc_codec.c

@@ -169,7 +169,8 @@ e_ipc_codec_str_list_dec(char *data, int bytes, Evas_List **dest)
      {
         E_Ipc_Str *str_node;
 	
-        str_node->str = l->data;
+	str_node = malloc(sizeof(E_Ipc_Str));
+        str_node = l->data;
 	list = evas_list_append(list, str_node->str);
      }
    if (dest) *dest = list;