diff --git a/src/calibre/devices/usbms/deviceconfig.py b/src/calibre/devices/usbms/deviceconfig.py
index 3c79652463..3f669f1e24 100644
--- a/src/calibre/devices/usbms/deviceconfig.py
+++ b/src/calibre/devices/usbms/deviceconfig.py
@@ -94,6 +94,9 @@ class DeviceConfig(object):
             if isinstance(cls.EXTRA_CUSTOMIZATION_MESSAGE, list):
                 ec = []
                 for i in range(0, len(cls.EXTRA_CUSTOMIZATION_MESSAGE)):
+                    if config_widget.opt_extra_customization[i] is None:
+                        ec.append(None)
+                        continue
                     if hasattr(config_widget.opt_extra_customization[i], 'isChecked'):
                         ec.append(config_widget.opt_extra_customization[i].isChecked())
                     else:
diff --git a/src/calibre/devices/user_defined/driver.py b/src/calibre/devices/user_defined/driver.py
index 3211bd19ef..f57f61fe7c 100644
--- a/src/calibre/devices/user_defined/driver.py
+++ b/src/calibre/devices/user_defined/driver.py
@@ -15,7 +15,7 @@ class USER_DEFINED(USBMS):
     supported_platforms = ['windows', 'osx', 'linux']
 
     # Ordered list of supported formats
-    FORMATS     = BOOK_EXTENSIONS
+    FORMATS     = ['epub', 'mobi', 'pdf']
 
     VENDOR_ID   = 0xFFFF
     PRODUCT_ID  = 0xFFFF
@@ -35,42 +35,44 @@ class USER_DEFINED(USBMS):
     SUPPORTS_SUB_DIRS = True
 
     EXTRA_CUSTOMIZATION_MESSAGE = [
-        _('USB Vendor ID (in hex)') + ':::' +
+        _('USB Vendor ID (in hex)') + ':::<p>' +
             _('Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('USB Product ID (in hex)')+ ':::' +
+              'set up the user-defined device') + '</p>',
+        _('USB Product ID (in hex)')+ ':::<p>' +
             _('Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('USB Revision ID (in hex)')+ ':::' +
+              'set up the user-defined device') + '</p>',
+        _('USB Revision ID (in hex)')+ ':::<p>' +
             _('Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('Windows main memory vendor string') + ':::' +
+              'set up the user-defined device') + '</p>',
+        '',
+        _('Windows main memory vendor string') + ':::<p>' +
             _('This field is used only on windows. '
               'Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('Windows main memory ID string') + ':::' +
+              'set up the user-defined device') + '</p>',
+        _('Windows main memory ID string') + ':::<p>' +
             _('This field is used only on windows. '
               'Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('Windows card A vendor string') + ':::' +
+              'set up the user-defined device') + '</p>',
+        _('Windows card A vendor string') + ':::<p>' +
             _('This field is used only on windows. '
               'Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('Windows card A ID string') + ':::' +
+              'set up the user-defined device') + '</p>',
+        _('Windows card A ID string') + ':::<p>' +
             _('This field is used only on windows. '
               'Get this ID using Preferences -> Misc -> Get information to '
-              'set up the user-defined device'),
-        _('Main memory folder') + ':::' +
+              'set up the user-defined device') + '</p>',
+        _('Main memory folder') + ':::<p>' +
             _('Enter the folder where the books are to be stored. This folder '
-              'is prepended to any send_to_device template'),
-        _('Card A folder') + ':::' +
+              'is prepended to any send_to_device template') + '</p>',
+        _('Card A folder') + ':::<p>' +
             _('Enter the folder where the books are to be stored. This folder '
-              'is prepended to any send_to_device template'),
+              'is prepended to any send_to_device template') + '</p>',
     ]
     EXTRA_CUSTOMIZATION_DEFAULT = [
                 '0x0000',
                 '0x0000',
                 '0x0000',
+                None,
                 '',
                 '',
                 '',
@@ -81,12 +83,12 @@ class USER_DEFINED(USBMS):
     OPT_USB_VENDOR_ID           = 0
     OPT_USB_PRODUCT_ID          = 1
     OPT_USB_REVISION_ID         = 2
-    OPT_USB_WINDOWS_MM_VEN_ID   = 3
-    OPT_USB_WINDOWS_MM_ID       = 4
-    OPT_USB_WINDOWS_CA_VEN_ID   = 5
-    OPT_USB_WINDOWS_CA_ID       = 6
-    OPT_MAIN_MEM_FOLDER         = 7
-    OPT_CARD_A_FOLDER           = 8
+    OPT_USB_WINDOWS_MM_VEN_ID   = 4
+    OPT_USB_WINDOWS_MM_ID       = 5
+    OPT_USB_WINDOWS_CA_VEN_ID   = 6
+    OPT_USB_WINDOWS_CA_ID       = 7
+    OPT_MAIN_MEM_FOLDER         = 8
+    OPT_CARD_A_FOLDER           = 9
 
     def initialize(self):
         try:
diff --git a/src/calibre/gui2/device_drivers/configwidget.py b/src/calibre/gui2/device_drivers/configwidget.py
index fc7e16e639..e55a0c6dda 100644
--- a/src/calibre/gui2/device_drivers/configwidget.py
+++ b/src/calibre/gui2/device_drivers/configwidget.py
@@ -62,8 +62,18 @@ class ConfigWidget(QWidget, Ui_ConfigWidget):
 
             if isinstance(extra_customization_message, list):
                 self.opt_extra_customization = []
+                if len(extra_customization_message) > 6:
+                    row_func = lambda x, y: ((x/2) * 2) + y
+                    col_func = lambda x: x%2
+                else:
+                    row_func = lambda x, y: x*2 + y
+                    col_func = lambda x: 0
+
                 for i, m in enumerate(extra_customization_message):
                     label_text, tt = parse_msg(m)
+                    if not label_text:
+                        self.opt_extra_customization.append(None)
+                        continue
                     if isinstance(settings.extra_customization[i], bool):
                         self.opt_extra_customization.append(QCheckBox(label_text))
                         self.opt_extra_customization[-1].setToolTip(tt)
@@ -75,8 +85,9 @@ class ConfigWidget(QWidget, Ui_ConfigWidget):
                         l.setBuddy(self.opt_extra_customization[i])
                         l.setWordWrap(True)
                         self.opt_extra_customization[i].setText(settings.extra_customization[i])
-                        self.extra_layout.addWidget(l)
-                    self.extra_layout.addWidget(self.opt_extra_customization[i])
+                        self.extra_layout.addWidget(l, row_func(i, 0), col_func(i))
+                    self.extra_layout.addWidget(self.opt_extra_customization[i],
+                                                row_func(i, 1), col_func(i))
             else:
                 self.opt_extra_customization = QLineEdit()
                 label_text, tt = parse_msg(extra_customization_message)
@@ -86,8 +97,8 @@ class ConfigWidget(QWidget, Ui_ConfigWidget):
                 l.setWordWrap(True)
                 if settings.extra_customization:
                     self.opt_extra_customization.setText(settings.extra_customization)
-                self.extra_layout.addWidget(l)
-                self.extra_layout.addWidget(self.opt_extra_customization)
+                self.extra_layout.addWidget(l, 0, 0)
+                self.extra_layout.addWidget(self.opt_extra_customization, 1, 0)
         self.opt_save_template.setText(settings.save_template)
 
 
diff --git a/src/calibre/gui2/device_drivers/configwidget.ui b/src/calibre/gui2/device_drivers/configwidget.ui
index 619d7052e8..92324fd1a7 100644
--- a/src/calibre/gui2/device_drivers/configwidget.ui
+++ b/src/calibre/gui2/device_drivers/configwidget.ui
@@ -101,7 +101,7 @@
     </widget>
    </item>
    <item row="6" column="0">
-    <layout class="QVBoxLayout" name="extra_layout"/>
+    <layout class="QGridLayout" name="extra_layout"/>
    </item>
    <item row="4" column="0">
     <widget class="QLabel" name="label">