diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index 30629161db..a4d9486e68 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -298,8 +298,9 @@ class USBMS(CLI, Device):
         # Clear the _new_book indication, as we are supposed to be done with
         # adding books at this point
         for blist in booklists:
-            for book in blist:
-                book._new_book = False
+            if blist is not None:
+                for book in blist:
+                    book._new_book = False
 
         self.report_progress(1.0, _('Sending metadata to device...'))
         debug_print('USBMS: finished sync_booklists')
diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index 33ee25c433..9050c7dbd1 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -148,8 +148,8 @@ class FormatList(QListWidget):
 
 class ImageView(QLabel):
 
-    MAX_WIDTH  = 400
-    MAX_HEIGHT = 300
+    MAX_WIDTH  = 600
+    MAX_HEIGHT = 800
     DROPABBLE_EXTENSIONS = IMAGE_EXTENSIONS
 
     @classmethod