pm-suspend crashes sometimes (removing triggers)

happens approx one out of ten times.
afterwards, system wont suspend anymore.

from syslog:
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.217843] general protection fault: 0000 [#1] SMP
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.217922] CPU 2
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.217944] Modules linked in: bnep rfcomm bluetooth parport_pc ppdev binfmt_misc
snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep cdc_ether snd_pcm uvcvideo videodev ums_realtek usbnet v4l2_compat_
ioctl32 snd_seq_midi cdc_acm cdc_wdm uas joydev snd_rawmidi snd_seq_midi_event dm_multipath snd_seq lib80211_crypt_tkip i915 psm
ouse snd_timer snd_seq_device intel_ips drm_kms_helper serio_raw sparse_keymap wl(P) snd drm i2c_algo_bit mei(C) mac_hid video w
mi soundcore snd_page_alloc lib80211 lp parport usb_storage tg3 dm_raid45 xor dm_mirror dm_region_hash dm_log
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.218781]
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.218803] Pid: 13719, comm: pm-suspend Tainted: P C O 3.2.0-26-generic #
41-Ubuntu Acer TravelMate 8172/TravelMate 8172
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.218916] RIP: 0010:[<ffffffff81513dcd>] [<ffffffff81513dcd>] led_trigger_unreg
ister+0x3d/0xe0
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219004] RSP: 0018:ffff88019e833ca8 EFLAGS: 00010296
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219051] RAX: dead000000200200 RBX: ffff8801e892ffc0 RCX: 0000000000000008
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219111] RDX: dead000000100100 RSI: dead000000100100 RDI: dead000000200200
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219171] RBP: ffff88019e833cc8 R08: ffffffff81cdda20 R09: 0000000000000100
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219230] R10: 0000000000000008 R11: 0000000000000001 R12: ffff88022ae49820
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219289] R13: ffff8801e892ffc0 R14: ffff88022e2fd378 R15: 0000000000000000
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219349] FS: 00007ffba2e8d700(0000) GS:ffff88023bc80000(0000) knlGS:0000000000
000000
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219415] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219465] CR2: 00007f6025b23020 CR3: 00000001da161000 CR4: 00000000000006e0
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219524] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219584] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219643] Process pm-suspend (pid: 13719, threadinfo ffff88019e832000, task ffff8801e88edbc0)
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219713] Stack:
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219736] ffff88022e2fd378 ffff8801e892ffc0 ffff88022ae49820 00000000fffffffe
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219827] ffff88019e833ce8 ffffffff81513e8b ffff88022c9e3010 ffff88022ae49840
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.219916] ffff88019e833d08 ffffffff814dc61c ffff88019e833d08 ffff88022ae49840
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220005] Call Trace:
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220035] [<ffffffff81513e8b>] led_trigger_unregister_simple+0x1b/0x30
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220097] [<ffffffff814dc61c>] power_supply_remove_triggers+0x4c/0xb0
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220155] [<ffffffff814db996>] power_supply_unregister+0x36/0x50
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220214] [<ffffffff81397ff7>] sysfs_remove_battery+0x3c/0x54
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220269] [<ffffffff81398cd2>] battery_notify+0x2e/0x3d
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220324] [<ffffffff8165d8fd>] notifier_call_chain+0x4d/0x70
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220382] [<ffffffff81090798>] __blocking_notifier_call_chain+0x58/0x80
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220443] [<ffffffff810907d6>] blocking_notifier_call_chain+0x16/0x20
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220503] [<ffffffff810aa38a>] pm_notifier_call_chain+0x1a/0x30
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220586] [<ffffffff810ab64b>] enter_state+0xfb/0x110
JuJul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220815] [<ffffffff811ebf5f>] sysfs_write_file+0xef/0x170
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220896] [<ffffffff81177f63>] vfs_write+0xb3/0x180
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220966] [<ffffffff8117828a>] sys_write+0x4a/0x90
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.221037] [<ffffffff81661fc2>] system_call_fastpath+0x16/0x1b
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.221115] Code: 49 89 fd 48 c7 c7 20 af c9 81 e8 9f 4e 14 00 49 8b 45 38 49 8b 55 30 48 be 00 01 10 00 00 00 ad de 48 bf 00 02 20 00 00 00 ad de <48> 89 42 08 48 89 10 49 89 75 30 49 89 7d 38 48 c7 c7 20 af c9
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.221853] RIP [<ffffffff81513dcd>] led_trigger_unregister+0x3d/0xe0
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.221953] RSP <ffff88019e833ca8>
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.225580] ---[ end trace 9285cfef3511d90c ]---
l 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220657] [<ffffffff810a9fe7>] state_store+0xb7/0x130
Jul 7 11:31:17 aj-TravelMate-8172 kernel: [11646.220734] [<ffffffff8130ce2f>] kobj_attr_store+0xf/0x30

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: pm-utils 1.4.1-9
ProcVersionSignature: Ubuntu 3.2.0-26.41-generic 3.2.19
Uname: Linux 3.2.0-26-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Mon Jul 16 16:37:25 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: pm-utils
UpgradeStatus: No upgrade log present (probably fresh install)
---
ApportVersion: 2.6.1-0ubuntu13
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: aj 2656 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
DistroRelease: Ubuntu 12.10
HibernationDevice: RESUME=UUID=fb08d092-f012-4e36-b866-899e98c13c83
InstallationDate: Installed on 2012-07-04 (884 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MachineType: Acer TravelMate 8172
MarkForUpload: True
NonfreeKernelModules: wl
Package: linux (not installed)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-43-generic root=UUID=abca279f-e1b5-4292-863f-002cbba31bee ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.5.0-43.66-generic 3.5.7.23
RelatedPackageVersions:
 linux-restricted-modules-3.5.0-43-generic N/A
 linux-backports-modules-3.5.0-43-generic N/A
 linux-firmware 1.95.1
RfKill:
 0: brcmwl-0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
Tags: quantal running-unity
Uname: Linux 3.5.0-43-generic x86_64
UpgradeStatus: Upgraded to quantal on 2012-12-01 (734 days ago)
UserGroups: adm cdrom dialout dip lpadmin plugdev sambashare sudo
dmi.bios.date: 03/31/2011
dmi.bios.vendor: Acer
dmi.bios.version: V1.15
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: TravelMate 8172
dmi.board.vendor: Acer
dmi.board.version: PSMBOU-1234567
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: None
dmi.modalias: dmi:bvnAcer:bvrV1.15:bd03/31/2011:svnAcer:pnTravelMate8172:pvrV1.15:rvnAcer:rnTravelMate8172:rvrPSMBOU-1234567:cvnAcer:ct10:cvrNone:
dmi.product.name: TravelMate 8172
dmi.product.version: V1.15
dmi.sys.vendor: Acer