diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 63e11ae368..d18d1a4479 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -32,9 +32,6 @@ Run an embedded python interpreter.
             help='Add a simple plugin (i.e. a plugin that consists of only a '
             '.py file), by specifying the path to the py file containing the '
             'plugin code.')
-    parser.add_option('--pdfreflow', default=None,
-            help='Path to PDF file to try and reflow. Output will be placed in '
-            'current directory. ')
 
     return parser
 
@@ -117,11 +114,6 @@ def main(args=sys.argv):
         prints('CALIBRE_RESOURCES_PATH='+sys.resources_location)
         prints('CALIBRE_EXTENSIONS_PATH='+sys.extensions_location)
         prints('CALIBRE_PYTHON_PATH='+os.pathsep.join(sys.path))
-    elif opts.pdfreflow:
-        from calibre.ebooks.pdf.reflow import option_parser as px, run
-        from calibre.utils.logging import default_log
-        opts2, args = px().parse_args(['xxxx', '-vvvv', opts.pdfreflow])
-        run(opts2, opts.pdfreflow, default_log)
     else:
         from calibre import ipython
         ipython()
diff --git a/src/calibre/devices/cybook/driver.py b/src/calibre/devices/cybook/driver.py
index 5ac0d4999c..8790cea6b8 100644
--- a/src/calibre/devices/cybook/driver.py
+++ b/src/calibre/devices/cybook/driver.py
@@ -34,6 +34,7 @@ class CYBOOK(USBMS):
     VENDOR_NAME = 'BOOKEEN'
     WINDOWS_MAIN_MEM = re.compile(r'CYBOOK_(OPUS|GEN3)__-FD')
     WINDOWS_CARD_A_MEM = re.compile('CYBOOK_(OPUS|GEN3)__-SD')
+    OSX_MAIN_MEM_VOL_PAT = re.compile(r'/Cybook')
 
     EBOOK_DIR_MAIN = 'eBooks'
     EBOOK_DIR_CARD_A = 'eBooks'
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index f01133c301..fd7cf262dc 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -71,6 +71,11 @@ class Device(DeviceConfig, DevicePlugin):
     OSX_CARD_A_MEM = None
     OSX_CARD_B_MEM = None
 
+    # Used by the new driver detection to disambiguate main memory from
+    # storage cards. Should be a regular expression that matches the
+    # main memory mount point assigned by OS X
+    OSX_MAIN_MEM_VOL_PAT = None
+
     MAIN_MEMORY_VOLUME_LABEL  = ''
     STORAGE_CARD_VOLUME_LABEL = ''
     STORAGE_CARD2_VOLUME_LABEL = None
@@ -415,6 +420,16 @@ class Device(DeviceConfig, DevicePlugin):
         if len(matches) > 2:
             drives['cardb'] = matches[2]
 
+        pat = self.OSX_MAIN_MEM_VOL_PAT
+        if pat is not None and len(drives) > 1 and 'main' in drives:
+            if pat.search(drives['main']) is None:
+                main = drives['main']
+                for x in ('carda', 'cardb'):
+                    if x in drives and pat.search(drives[x]):
+                        drives['main'] = drives.pop(x)
+                        drives[x] = main
+                        break
+
         return drives
 
     def osx_bsd_names(self):