Firefox is blocked by JS GC Helper

[Andreas E.]

Firefox sometimes freezes and turns gray when the process "JS GC Helper" is active. This is not a temporary freeze, but blocks Firefox completely until you close it.

There are two ways you could force quit Firefox:
1. By killing "firefox" in the system monitor, "JS GC Helper" won't be killed, and upon restart Firefox will tell that another instance is running (because its lock file hasn't yet released).
2. By killing "JS GC Helper", firefox closes also and you can restart it.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: firefox 20.0+build1-0ubuntu0.12.10.3
ProcVersionSignature: Ubuntu 3.5.0-27.46-generic 3.5.7.7
Uname: Linux 3.5.0-27-generic i686
AddonCompatCheckDisabled: False
ApportVersion: 2.6.1-0ubuntu10
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: andreas 2412 F.... pulseaudio
BuildID: 20130329030414
CRDA:
 country DE:
  (2400 - 2483 @ 40), (N/A, 20)
  (5150 - 5250 @ 40), (N/A, 20), NO-OUTDOOR
  (5250 - 5350 @ 40), (N/A, 20), NO-OUTDOOR, DFS
  (5470 - 5725 @ 40), (N/A, 26), DFS
Channel: Unavailable
Date: Thu Apr 11 18:01:02 2013
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IpRoute:
 default via 131.246.39.254 dev wlan0 proto static
 131.246.32.0/21 dev wlan0 proto kernel scope link src 131.246.38.154 metric 9
 169.254.0.0/16 dev wlan0 scope link metric 1000
MarkForUpload: True
MostRecentCrashID: bp-b81166f7-08ae-49e2-a097-e19d72130411
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=20.0/20130329030414
RelatedPackageVersions: rhythmbox-mozilla 2.97-1ubuntu6.1
RunningIncompatibleAddons: False
SourcePackage: firefox
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/25/2006
dmi.bios.vendor: Phoenix Technologies LTD
dmi.bios.version: Q3B21
dmi.board.name: PRO600IW
dmi.board.vendor: MAXDATA
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 1
dmi.chassis.vendor: No Enclosure
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnPhoenixTechnologiesLTD:bvrQ3B21:bd08/25/2006:svnMAXDATA:pnPRO600IW:pvr5123660003:rvnMAXDATA:rnPRO600IW:rvrNotApplicable:cvnNoEnclosure:ct1:cvrN/A:
dmi.product.name: PRO600IW
dmi.product.version: 5123660003
dmi.sys.vendor: MAXDATA

[Launchpad Janitor (janitor)]

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