diff --git a/src/calibre/devices/android/driver.py b/src/calibre/devices/android/driver.py
index 4316741755..54ea5c4cd2 100644
--- a/src/calibre/devices/android/driver.py
+++ b/src/calibre/devices/android/driver.py
@@ -21,7 +21,7 @@ class ANDROID(USBMS):
             0x0bb4 : { 0x0c02 : [0x100], 0x0c01 : [0x100]},
 
             # Motorola
-            0x22b8 : { 0x41d9 : [0x216], 0x2d67 : [0x100]},
+            0x22b8 : { 0x41d9 : [0x216], 0x2d67 : [0x100], 0x41db : [0x216]},
 
             0x18d1 : { 0x4e11 : [0x0100, 0x226], 0x4e12: [0x0100, 0x226]},
 
diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index c7334b1585..6c432fcb2f 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -1048,18 +1048,25 @@ class Manifest(object):
                 self._data = None
             return property(fget, fset, fdel, doc=doc)
 
-        def unload_data_from_memory(self):
+        def unload_data_from_memory(self, memory=None):
             if isinstance(self._data, (str, bytes)):
-                from calibre.ptempfile import PersistentTemporaryFile
-                pt = PersistentTemporaryFile('_oeb_base_mem_unloader')
-                pt.write(self._data)
-                pt.close()
-                def loader(*args):
-                    with open(pt.name, 'rb') as f:
-                        ans = f.read()
-                    os.remove(pt.name)
-                    return ans
-                self._loader = loader
+                if memory is None:
+                    from calibre.ptempfile import PersistentTemporaryFile
+                    pt = PersistentTemporaryFile(suffix='_oeb_base_mem_unloader.img')
+                    pt.write(self._data)
+                    pt.close()
+                    def loader(*args):
+                        with open(pt.name, 'rb') as f:
+                            ans = f.read()
+                        os.remove(pt.name)
+                        return ans
+                    self._loader = loader
+                else:
+                    def loader2(*args):
+                        with open(memory, 'rb') as f:
+                            ans = f.read()
+                        return ans
+                    self._loader = loader2
                 self._data = None
 
 
diff --git a/src/calibre/ebooks/oeb/output.py b/src/calibre/ebooks/oeb/output.py
index 123d485b00..b1de3b97a1 100644
--- a/src/calibre/ebooks/oeb/output.py
+++ b/src/calibre/ebooks/oeb/output.py
@@ -48,5 +48,6 @@ class OEBOutput(OutputFormatPlugin):
                     os.makedirs(dir)
                 with open(path, 'wb') as f:
                     f.write(str(item))
+                item.unload_data_from_memory(memory=path)
 
 
diff --git a/src/calibre/library/custom_columns.py b/src/calibre/library/custom_columns.py
index 812a8a9ba3..052143a5f6 100644
--- a/src/calibre/library/custom_columns.py
+++ b/src/calibre/library/custom_columns.py
@@ -189,8 +189,6 @@ class CustomColumns(object):
         if label is not None:
             self.conn.execute('UPDATE custom_columns SET label=? WHERE id=?',
                     (label, num))
-            self.custom_column_num_map[num]['label'] = label
-            self.custom_column_label_map[label] = self.custom_column_num_map[num]
             changed = True
         if is_editable is not None:
             self.conn.execute('UPDATE custom_columns SET is_editable=? WHERE id=?',
@@ -317,7 +315,8 @@ class CustomColumns(object):
             editable=True, display={}):
         if datatype not in self.CUSTOM_DATA_TYPES:
             raise ValueError('%r is not a supported data type'%datatype)
-        normalized  = datatype not in ('datetime', 'comments', 'int', 'bool')
+        normalized  = datatype not in ('datetime', 'comments', 'int', 'bool',
+                'float')
         is_multiple = is_multiple and datatype in ('text',)
         num = self.conn.execute(
                 ('INSERT INTO '