diff --git a/src/calibre/customize/ui.py b/src/calibre/customize/ui.py
index 04f9b80529..22885edf24 100644
--- a/src/calibre/customize/ui.py
+++ b/src/calibre/customize/ui.py
@@ -289,6 +289,7 @@ def available_input_formats():
         if not is_disabled(plugin):
             for format in plugin.file_types:
                 formats.add(format)
+    formats.add('zip'), formats.add('rar')
     return formats
 
 def output_format_plugins():
diff --git a/src/calibre/devices/prs500/driver.py b/src/calibre/devices/prs500/driver.py
index 5c97144049..73dd5b543d 100644
--- a/src/calibre/devices/prs500/driver.py
+++ b/src/calibre/devices/prs500/driver.py
@@ -239,6 +239,8 @@ class PRS500(DeviceConfig, DevicePlugin):
         Also initialize the device.
         See the source code for the sequence of initialization commands.
         """
+        if not hasattr(self, 'key'):
+            self.key = '-1\0\0\0\0\0\0'
         self.device = get_device_by_id(self.VENDOR_ID, self.PRODUCT_ID)
         if not self.device:
             raise DeviceError()
diff --git a/src/calibre/gui2/device.py b/src/calibre/gui2/device.py
index 1f0b315df6..3a46352a70 100644
--- a/src/calibre/gui2/device.py
+++ b/src/calibre/gui2/device.py
@@ -812,9 +812,9 @@ class DeviceGUI(object):
             bad = '\n'.join('%s'%(i,) for i in bad)
             d = warning_dialog(self, _('No suitable formats'),
                     _('Could not upload the following books to the device, '
-                'as no suitable formats were found. Try changing the output '
-                'format in the upper right corner next to the red heart and '
-                're-converting.'), bad)
+                'as no suitable formats were found. Convert the book(s) to a '
+                'format supported by your device first.'
+                ), bad)
             d.exec_()
 
     def upload_booklists(self):