Firefox's configured search engines overwritten after upgrade

[Filiprino]

After every upgrade I lose my configured search engines and there are new engines I never configured to be there, or my configured engines are out of order along with the new engines. This is annoying and I'm fed up with it. There are other reported bugs (for example #858683), but those seem to note a problem when switching between Ubuntu versions. This is not the case. This is between Firefox versions and has been occurring me since a long time ago.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: firefox 13.0.1+build1-0ubuntu0.12.04.1
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Uname: Linux 3.2.0-26-generic x86_64
NonfreeKernelModules: nvidia
AddonCompatCheckDisabled: False
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: filiprino 2360 F.... pulseaudio
 /dev/snd/controlC0: filiprino 2360 F.... pulseaudio
BuildID: 20120615112143
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf7ff8000 irq 46'
   Mixer name : 'Analog Devices AD1988B'
   Components : 'HDA:11d4198b,104381f2,00100300'
   Controls : 49
   Simple ctrls : 26
Card1.Amixer.info:
 Card hw:1 'NVidia'/'HDA NVidia at 0xfbcfc000 irq 17'
   Mixer name : 'Nvidia GPU 12 HDMI/DP'
   Components : 'HDA:10de0012,10de0101,00100100'
   Controls : 24
   Simple ctrls : 4
Channel: release
Date: Wed Jul 11 19:20:06 2012
ForcedLayersAccel: False
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
IpRoute:
 default via 172.28.64.1 dev eth1 proto static
 169.254.0.0/16 dev eth1 scope link metric 1000
 172.28.64.0/24 dev eth1 proto kernel scope link src 172.28.64.11 metric 1
IwConfig:
 lo no wireless extensions.

 eth1 no wireless extensions.

 eth0 no wireless extensions.
ProcEnviron:
 PATH=(custom, user)
 LANG=es_ES.UTF-8
 SHELL=/bin/bash
Profiles: Profile0 (Default) - LastVersion=13.0.1/20120615112143 (In use)
RelatedPackageVersions:
 gnome-shell 3.4.1-0ubuntu2
 rhythmbox-mozilla 2.96-0ubuntu4
 totem-mozilla 3.0.1-0ubuntu21
 sun-java6-bin 6.26-1natty1
RfKill:

RunningIncompatibleAddons: False
SourcePackage: firefox
UpgradeStatus: Upgraded to precise on 2012-06-17 (23 days ago)
dmi.bios.date: 12/22/2008
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1901
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: Commando
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1901:bd12/22/2008:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnCommando:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.