diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 2bebda380a..aedc3abcf3 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -2,7 +2,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
 __appname__   = 'calibre'
-__version__   = '0.5.9'
+__version__   = '0.5.10'
 __author__    = "Kovid Goyal <kovid@kovidgoyal.net>"
 '''
 Various run time constants.
diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 9dee6b2a86..35fc615b58 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -117,6 +117,7 @@ def debug_device_driver():
             print 'Trying to open device...'
             d = dev()
             d.open()
+            print 'Main memory:', repr(d._main_prefix)
             print 'Total space:', d.total_space()
             break
 
diff --git a/src/calibre/devices/eb600/driver.py b/src/calibre/devices/eb600/driver.py
index 638dea42ba..c390ce582f 100644
--- a/src/calibre/devices/eb600/driver.py
+++ b/src/calibre/devices/eb600/driver.py
@@ -2,6 +2,13 @@ __license__   = 'GPL v3'
 __copyright__ = '2009, Kovid Goyal <kovid@kovidgoyal.net>'
 '''
 Device driver for the Netronix EB600
+
+Windows PNP strings:
+ ('USBSTOR\\DISK&VEN_NETRONIX&PROD_EBOOK&REV_062E\\6&1A275569&0&EB6001009
+2W00000&0', 2, u'F:\\')
+        ('USBSTOR\\DISK&VEN_NETRONIX&PROD_EBOOK&REV_062E\\6&1A275569&0&EB6001009
+2W00000&1', 3, u'G:\\')
+
 '''
 
 from calibre.devices.usbms.driver import USBMS
@@ -35,8 +42,8 @@ class EB600(USBMS):
     SUPPORTS_SUB_DIRS = True
 
     def windows_sort_drives(self, drives):
-        main = drives['main']
-        card = drives['carda']
+        main = drives.get('main', None)
+        card = drives.get('card', None)
         if card and main and card < main:
             drives['main'] = card
             drives['carda'] = main
diff --git a/src/calibre/devices/jetbook/driver.py b/src/calibre/devices/jetbook/driver.py
index 8540a6d36d..d2054cd7a1 100644
--- a/src/calibre/devices/jetbook/driver.py
+++ b/src/calibre/devices/jetbook/driver.py
@@ -29,9 +29,6 @@ class JETBOOK(USBMS):
     WINDOWS_MAIN_MEM = 'EBOOK'
     WINDOWS_CARD_MEM = 'EBOOK'
 
-    WINDOWS_MAIN_MEM = None
-    WINDOWS_CARD_MEM = None
-
     OSX_MAIN_MEM = None
     OSX_CARD_MEM = None
 
@@ -116,8 +113,8 @@ class JETBOOK(USBMS):
         return mi
 
     def windows_sort_drives(self, drives):
-        main = drives['main']
-        card = drives['card']
+        main = drives.get('main', None)
+        card = drives.get('card', None)
         if card and main and card < main:
             drives['main'] = card
             drives['card'] = main
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index c4bbe7839f..8e3d51deca 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -8,11 +8,11 @@ device. This class handles device detection.
 
 import os, subprocess, time, re
 
-from calibre.devices.interface import DevicePlugin as Device
+from calibre.devices.interface import DevicePlugin
 from calibre.devices.errors import DeviceError
 from calibre import iswindows, islinux, isosx, __appname__
 
-class Device(Device):
+class Device(DevicePlugin):
     '''
     This class provides logic common to all drivers for devices that export themselves
     as USB Mass Storage devices. If you are writing such a driver, inherit from this
@@ -122,7 +122,7 @@ class Device(Device):
 
     @classmethod
     def _windows_space(cls, prefix):
-        if prefix is None:
+        if not prefix:
             return 0, 0
         win32file = __import__('win32file', globals(), locals(), [], -1)
         try:
@@ -221,16 +221,16 @@ class Device(Device):
             if 'main' in drives.keys() and 'carda' in drives.keys() and 'cardb' in drives.keys():
                 break
 
-        drives = self.windows_sort_drives(drives)
-        self._main_prefix = drives.get('main')
-        self._card_a_prefix = drives.get('carda')
-        self._card_b_prefix = drives.get('cardb')
-
-        if not self._main_prefix:
+        if 'main' not in drives:
             raise DeviceError(
                 _('Unable to detect the %s disk drive. Try rebooting.') %
                 self.__class__.__name__)
 
+        drives = self.windows_sort_drives(drives)
+        self._main_prefix = drives.get('main')
+        self._card_a_prefix = drives.get('carda', None)
+        self._card_b_prefix = drives.get('cardb', None)
+
     def get_osx_mountpoints(self, raw=None):
         if raw is None:
             ioreg = '/usr/sbin/ioreg'
@@ -272,16 +272,16 @@ class Device(Device):
         self._main_prefix = re.search(main_pat, mount).group(2) + os.sep
         card_a_pat = names['carda'] if 'carda' in names.keys() else None
         card_b_pat = names['cardb'] if 'cardb' in names.keys() else None
-        
+
         def get_card_prefix(pat):
             if pat is not None:
                 pat = dev_pat % pat
                 return re.search(pat, mount).group(2) + os.sep
             else:
                 return None
-                
+
         self._card_a_prefix = get_card_prefix(card_a_pat)
-        self._card_b_prefix = get_card_prefix(card_b_pat) 
+        self._card_b_prefix = get_card_prefix(card_b_pat)
 
     def open_linux(self):
         import dbus
diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index 7649f44612..40a22c662e 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -38,10 +38,6 @@ class USBMS(CLI, Device):
                         report_progress=report_progress)
 
     def get_device_information(self, end_session=True):
-        """
-        Ask device for device information. See L{DeviceInfoQuery}.
-        @return: (device name, device version, software version on device, mime type)
-        """
         return (self.__class__.__name__, '', '', '')
 
     def books(self, oncard=None, end_session=True):