Comment 4 for bug 665651

Had the same problem in xubuntu 11.04.

Published patch corrects pm-utils behaviour. I use a pm hook to umount SD cards on suspend, in order to avoid data corruption on resume (as described on https://bugs.launchpad.net/ubuntu/karmic/+source/linux/+bug/424877).

My hook looks like this:
#!/bin/sh
# Drop to: /etc/pm/sleep.d
# Use this script to prevent data loss on gnome-mounted MMC/SD
# cards. It syncs data and umounts all mmcblk devices prior to
# suspend, and cancels suspend if umounting was not posssible
# (i.e: something locks a file)
case "$1" in
 hibernate|suspend)
  sync
  for drive in $( ls /dev/mmcblk?p* ); do
      umount ${drive} > /dev/null
      # If umount failed: abort suspend
      if [ $? -gt 0 ]; then
   # Test if device keeps mounted. Previous command could fail
   # (i.e device was not mounted) with a non-stopper
   # problem for the suspend precess
   mount | grep ${drive}
   if [ $? -eq 0 ]; then
       echo "Failed to umount ${drive}" > /tmp/suspend.log
       exit 1
   fi
      fi
  done
  ;;
esac

My hook doesn't work without published patch, and without this hook data corruption is possible... so, I vote for high importance on this bug.