diff --git a/.gitignore b/.gitignore
index 8a49ae7..b17211c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 staging/
 sdcard/
-NookManager.img
+NookManager.img*
+build.sh?*
diff --git a/NookManager/menu/backup b/NookManager/menu/backup
index 15d5c00..3bde1fe 100644
--- a/NookManager/menu/backup
+++ b/NookManager/menu/backup
@@ -3,42 +3,36 @@ MENU=/tmp/sdcache/menu
 
 title="Create Backup"
 header=
-button1=
+button1="<- Erase empty storage (makes backup faster)"
+button2="Format remaining space on SD card ->"
 button3="<- Back"
-button2=
-button4=
+button4="Create backup ->"
 footer=
 key=0
 
 
 
-if [ ! -b /dev/block/mmcblk1p2 ]; then
-  header="Backups will be stored on this SD card.\nTo proceed, you must format the unused\nspace on this card."
-  button2="Format remaining space on SD card ->"
-else
-  header="It will take 15-45 minutes to create a backup."
-  button4="Create backup ->"
-fi
-
 until [ "$key" -eq "3" ]; do
+  if [ ! -b /dev/block/mmcblk1p2 ]; then
+    header="Backups will be stored on this SD card.\nTo proceed, you must format the unused\nspace on this card."
+  else
+    header="It will take 15-45 minutes to create a backup."
+  fi
+
   $SCRIPT/menu -t "$title" -h "$header" -f "$footer" -1 "$button1" -2 "$button2" -3 "$button3" -4 "$button4" 
   key=$?
 
   if [[ "$key" -eq "2" ]]; then
     $SCRIPT/menu -t "$title" -h "$header" -f "Formatting free space on SD card..."
     footer=`$SCRIPT/format_unused_sdcard`
-    header="It will take 15-45 minutes to create a backup."
-    button2=""
-    button4="Create backup ->"
+
+  elif [[ "$key" -eq "1" ]]; then
+    $SCRIPT/menu -t "$title" -h "$header" -f "Erasing empty storage areas..."
+    footer=`$SCRIPT/shrink_data`
 
   elif [[ "$key" -eq "4" ]]; then
     $SCRIPT/menu -t "$title" -h "$header" -f "Creating backup image...\nBackup started `date +%H:%M:%S`"
     footer=`$SCRIPT/create_backup`
-    # If the backup succeeded, hide the create backup button
-    if [ "$?" -eq "0" ]; then 
-      header=""
-      button4=""
-    fi
   fi
 
 done
diff --git a/NookManager/menu/mainmenu b/NookManager/menu/mainmenu
index 6f7f6e1..c5780f9 100644
--- a/NookManager/menu/mainmenu
+++ b/NookManager/menu/mainmenu
@@ -11,15 +11,19 @@ key=0
 while [ "$key" -ne "3" ]; do
 
   POWER=`cat  /sys/class/power_supply/bq27510-0/capacity`
+  CHARGING=`cat /sys/class/power_supply/bq27510-0/status`
 
-  if [ "$POWER" -lt "40" ]; then
-    header="System: $SYSTEM\nBattery Level: $POWER\nPlease charge your battery above 40\nand then restart NookManager."
+  POWERMSG="$POWER%%"
+  [ "" != "$CHARGING" ] && POWERMSG="$POWER%% ($CHARGING)"
+  header="System: $SYSTEM\nBattery Level: $POWERMSG"
+
+  if [ "$POWER" -lt "40" -a \( "$POWER" -lt 20 -o "$CHARGING" != "Charging" \) ]; then
+    header="$header\nPlease charge your battery above 40%%\n(or 20%% when plugged in to power)\nand then restart NookManager."
     button1=
     button3="<- Exit"
     button2=
     button4=
   else
-    header="System: $SYSTEM\nBattery Level: $POWER"
     button1="<- Rescue"
     button3="<- Exit"
     button2="Root ->"
diff --git a/NookManager/scripts/create_backup b/NookManager/scripts/create_backup
index 93ccfad..6e91b3e 100644
--- a/NookManager/scripts/create_backup
+++ b/NookManager/scripts/create_backup
@@ -7,26 +7,8 @@ umount /tmp/backups
 mkdir -p /tmp/backups
 mount -t vfat /dev/block/mmcblk1p2 /tmp/backups
 
-$SCRIPT/mount_nook
-
 echo Backup started `date +%H:%M:%S`
 
-# Zero the free space on each of the Nook's partitions 
-dd if=/dev/zero of=/nook/factory/DELETEME bs=512k
-rm /nook/factory/DELETEME
-
-dd if=/dev/zero of=/nook/system/DELETEME bs=512k
-rm /nook/system/DELETEME
-
-dd if=/dev/zero of=/nook/userdata/DELETEME bs=512k
-rm /nook/userdata/DELETEME
-
-dd if=/dev/zero of=/nook/cache/DELETEME bs=512k
-rm /nook/cache/DELETEME
-
-dd if=/dev/zero of=/nook/data/DELETEME bs=512k
-rm /nook/data/DELETEME
-
 sync
 
 dd if=/dev/block/mmcblk0 bs=1000k | gzip -1 > /tmp/backups/backup.full.gz
@@ -46,7 +28,6 @@ fi
 
 sync
 umount /tmp/backups
-$SCRIPT/umount_nook
 
 echo "/dev/block/mmcblk1p2" >  /sys/devices/platform/usb_mass_storage/lun1/file
 
diff --git a/NookManager/scripts/menu_draw b/NookManager/scripts/menu_draw
index df68030..57c8404 100644
--- a/NookManager/scripts/menu_draw
+++ b/NookManager/scripts/menu_draw
@@ -39,10 +39,10 @@ done
 -pointsize 45 \
 -draw "gravity North text 0,0 '$title'" \
 -pointsize 26 \
--draw "gravity West text 0,-100 '$button1' " \
--draw "gravity East text 0,-100 '$button2' " \
--draw "gravity West text 0,120  '$button3' " \
--draw "gravity East text 0,120  '$button4' " \
+-draw "gravity West text 0,-115 '$button1' " \
+-draw "gravity East text 0,-85  '$button2' " \
+-draw "gravity West text 0,105  '$button3' " \
+-draw "gravity East text 0,135  '$button4' " \
 -gravity north \
 -annotate +0+80 "$header" \
 -gravity south \
diff --git a/NookManager/scripts/shrink_data b/NookManager/scripts/shrink_data
new file mode 100755
index 0000000..07a3ec0
--- /dev/null
+++ b/NookManager/scripts/shrink_data
@@ -0,0 +1,28 @@
+SCRIPT=/tmp/sdcache/scripts
+
+$SCRIPT/mount_nook
+
+echo Backup started `date +%H:%M:%S`
+
+# Zero the free space on each of the Nook's partitions 
+# (described as "Erasing empty storage areas" on-screen)
+
+dd if=/dev/zero of=/nook/factory/DELETEME bs=512k
+rm /nook/factory/DELETEME
+
+dd if=/dev/zero of=/nook/system/DELETEME bs=512k
+rm /nook/system/DELETEME
+
+dd if=/dev/zero of=/nook/userdata/DELETEME bs=512k
+rm /nook/userdata/DELETEME
+
+dd if=/dev/zero of=/nook/cache/DELETEME bs=512k
+rm /nook/cache/DELETEME
+
+dd if=/dev/zero of=/nook/data/DELETEME bs=512k
+rm /nook/data/DELETEME
+
+sync
+$SCRIPT/umount_nook
+
+exit 0
diff --git a/build.sh b/build.sh
index 921fc4f..768e5bd 100755
--- a/build.sh
+++ b/build.sh
@@ -181,25 +181,28 @@ cp "$BDIR/patched-jars/android.policy.jar" "$OUTDIR/files/system/framework/"
 cp "$BDIR/patched-jars/services.jar" "$OUTDIR/files/system/framework/"
 
 # Create image
-dd if=/dev/zero of=NookManager.img bs=1MiB count=64
-losetup /dev/loop0 NookManager.img
-parted /dev/loop0 mklabel msdos
-parted /dev/loop0 --align=cyl mkpart primary fat32 0 100%
-parted /dev/loop0 set 1 boot on
-losetup -o 16384 /dev/loop1 /dev/loop0
-mkdosfs -F 32 -n "NookManager" /dev/loop1
+IMAGE_FILE=NookManager.img
+dd if=/dev/zero of=$IMAGE_FILE bs=1MiB count=64
+WHOLE_CARD=$(sudo losetup -f)
+sudo losetup $WHOLE_CARD $IMAGE_FILE
+BOOTFS_DEV=$(sudo losetup -f)
+sudo parted $WHOLE_CARD mklabel msdos
+sudo parted $WHOLE_CARD --align=minimal mkpart primary fat32 16384B 100%
+sudo parted $WHOLE_CARD set 1 boot on
+sudo losetup -o 16384 $BOOTFS_DEV $WHOLE_CARD
+sudo mkdosfs -F 32 -n "NookManager" $BOOTFS_DEV
 
 if [ ! -d "$BDIR/tmpmount" ]; then
   mkdir "$BDIR/tmpmount"
 fi
-mount -t vfat /dev/loop1 "$BDIR/tmpmount"
+sudo mount -t vfat -o uid=$(id -ur) -o gid=$(id -gr) $BOOTFS_DEV "$BDIR/tmpmount"
 
 rsync -a "$OUTDIR/" "$BDIR/tmpmount/"
 sync
-umount "$BDIR/tmpmount"
+sudo umount "$BDIR/tmpmount"
 
-losetup -d /dev/loop1
+sudo losetup -d $BOOTFS_DEV
 sync
-losetup -d /dev/loop0
+sudo losetup -d $WHOLE_CARD
 
-echo "Build Complete.  You can now flash NookManager.img to a SD card."
+echo "Build Complete.  You can now flash $IMAGE_FILE to an SD card."
diff --git a/readme.md b/readme.md
index 467455f..15e7684 100644
--- a/readme.md
+++ b/readme.md
@@ -1,5 +1,9 @@
 You must use a 32-bit Linux system to build this project.
 
+(Bela Lubkin notes: it built fine for me on Ubuntu 12.04 x86_64; not
+sure what the issue might be?  I do have 32-bit libraries installed for
+the benefit of various binary-only apps.)
+
 git clone https://github.com/doozan/NookManager.git
 
 cd NookManager