diff --git a/src/calibre/devices/usbms/cli.py b/src/calibre/devices/usbms/cli.py
index 40e2225486..d31b26d5f4 100644
--- a/src/calibre/devices/usbms/cli.py
+++ b/src/calibre/devices/usbms/cli.py
@@ -48,9 +48,9 @@ class CLI(object):
             (self._card_b_prefix and path.startswith(self._card_b_prefix))):
             path = self._main_prefix + path[1:]
         elif path.startswith('carda:'):
-            path = path.replace('carda:', self._card_prefix[:-1])
+            path = path.replace('carda:', self._card_a_prefix[:-1])
         elif path.startswith('cardb:'):
-            path = path.replace('cardb:', self._card_prefix[:-1])
+            path = path.replace('cardb:', self._card_b_prefix[:-1])
         return path
 
     def list(self, path, recurse=False, end_session=True, munge=True):
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index 04f99f0768..ba2fb1a5e0 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -174,7 +174,8 @@ class Device(DeviceConfig, DevicePlugin):
                 cbsz = stats.f_frsize * stats.f_bavail
         else:
             msz = self._windows_space(self._main_prefix)[1]
-            csz = self._windows_space(self._card_prefix)[1]
+            casz = self._windows_space(self._card_a_prefix)[1]
+            cbsz = self._windows_space(self._card_b_prefix)[1]
 
         return (msz, casz, cbsz)
 
diff --git a/src/calibre/utils/podofo/__init__.py b/src/calibre/utils/podofo/__init__.py
index 095160a639..9fc0c981e6 100644
--- a/src/calibre/utils/podofo/__init__.py
+++ b/src/calibre/utils/podofo/__init__.py
@@ -67,7 +67,6 @@ def get_metadata_quick(raw):
         mi.book_producer = creator
     return mi
 
-
 def get_metadata_(path, cpath=None):
     p = podofo.PDFDoc()
     p.open(path)