History on preferences reverts to use custom settings for history instead of never remember history

In Firefox preferences, the history reverts each time to use custom settings for history instead of never remember history. I'm using Firefox 13. I expect the history setting to remain on never remember history instead of use custom settings.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: firefox 13.0+build1-0ubuntu0.11.04.1
ProcVersionSignature: Ubuntu 2.6.38-15.60-generic-pae 2.6.38.8
Uname: Linux 2.6.38-15-generic-pae i686
AddonCompatCheckDisabled: False
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: VT1708BCE Analog [VT1708BCE Analog]
   Subdevices: 2/2
   Subdevice #0: subdevice #0
   Subdevice #1: subdevice #1
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: VT1708BCE Analog [VT1708BCE Analog]
   Subdevices: 2/2
   Subdevice #0: subdevice #0
   Subdevice #1: subdevice #1
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: john 2066 F.... pulseaudio
BuildID: 20120601175858
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfea78000 irq 42'
   Mixer name : 'VIA VT1708BCE'
   Components : 'HDA:1106e721,10192699,00100100'
   Controls : 28
   Simple ctrls : 17
Channel: release
Date: Fri Jun 8 02:57:39 2012
ForcedLayersAccel: False
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
IpRoute:
 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.6 metric 1
 169.254.0.0/16 dev eth0 scope link metric 1000
 default via 192.168.1.1 dev eth0 proto static
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.

 vboxnet0 no wireless extensions.
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Profiles: Profile0 (Default) - LastVersion=13.0/20120601175858 (In use)
RelatedPackageVersions:
 adobe-flashplugin 11.2.202.235-0natty1
 icedtea-plugin 1.1.1-0ubuntu1~11.04.2
 gecko-mediaplayer 1.0.0-0ubuntu2
 totem-mozilla 2.32.0-0ubuntu10
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
RunningIncompatibleAddons: False
SourcePackage: firefox
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/18/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 080014
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: G31T-M9
dmi.board.vendor: ECS
dmi.board.version: 1.0
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: ECS
dmi.chassis.version: 1.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr080014:bd05/18/2009:svnECS:pnG31T-M9:pvr1.0:rvnECS:rnG31T-M9:rvr1.0:cvnECS:ct3:cvr1.0:
dmi.product.name: G31T-M9
dmi.product.version: 1.0
dmi.sys.vendor: ECS