diff --git a/src/calibre/devices/prs500/cli/main.py b/src/calibre/devices/prs500/cli/main.py
index 74529c6d58..7603acb98a 100755
--- a/src/calibre/devices/prs500/cli/main.py
+++ b/src/calibre/devices/prs500/cli/main.py
@@ -180,7 +180,8 @@ def main():
     if not cols: # On windows terminal width is unknown
         cols = 80
 
-    parser = OptionParser(usage="usage: %prog [options] command args\n\ncommand is one of: info, books, df, ls, cp, mkdir, touch, cat, rm\n\n"+
+    parser = OptionParser(usage="usage: %prog [options] command args\n\ncommand "+
+            "is one of: info, books, df, ls, cp, mkdir, touch, cat, rm, eject\n\n"+
     "For help on a particular command: %prog command", version=__appname__+" version: " + __version__)
     parser.add_option("--log-packets", help="print out packet stream to stdout. "+\
                     "The numbers in the left column are byte offsets that allow the packet size to be read off easily.",
@@ -222,6 +223,8 @@ def main():
             for i in range(3):
                 print "%-10s\t%s\t%s\t%s\t%s"%(where[i], human_readable(total[i]), human_readable(total[i]-free[i]), human_readable(free[i]),\
                                                                             str(0 if total[i]==0 else int(100*(total[i]-free[i])/(total[i]*1.)))+"%")
+        elif command == 'eject':
+            dev.eject()
         elif command == "books":
             print "Books in main memory:"
             for book in dev.books():
diff --git a/src/calibre/devices/usbms/device.py b/src/calibre/devices/usbms/device.py
index e1e8f3890c..c4819307a4 100644
--- a/src/calibre/devices/usbms/device.py
+++ b/src/calibre/devices/usbms/device.py
@@ -7,7 +7,7 @@ intended to be subclassed with the relevant parts implemented for a particular
 device. This class handles device detection.
 '''
 
-import os, subprocess, time, re, sys, glob
+import os, subprocess, time, re, sys, glob, shutil
 from itertools import repeat
 
 from calibre.devices.interface import DevicePlugin
@@ -548,13 +548,23 @@ class Device(DeviceConfig, DevicePlugin):
         drives = self.find_device_nodes()
         for drive in drives:
             if drive:
-                cmd = ['pumount']
+                cmd = ['pumount', '-l']
                 try:
                     p = subprocess.Popen(cmd + [drive])
                 except:
                     pass
                 while p.poll() is None:
                     time.sleep(0.1)
+            if p.returncode == 0:
+                for x in ('_main_prefix', '_card_a_prefix', '_card_b_prefix'):
+                    x = getattr(self, x, None)
+                    if x is not None:
+                        if x.startswith('/media/') and os.path.exists(x):
+                            try:
+                                shutil.rmtree(x)
+                            except:
+                                pass
+
 
     def eject(self):
         if islinux: