the application freeze several times when using facebook

[Valmir Ademar Weide Knäsel Júnior]

When I'm accessing some sites like facebook and youtube, the browser freeze and then return to normal activity. It happens several times. I'm using ubuntu 11.10 with gnome-shell and firefox 9.0.1.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: firefox 9.0.1+build1-0ubuntu0.11.10.2
ProcVersionSignature: Ubuntu 3.0.0-14.23-generic 3.0.9
Uname: Linux 3.0.0-14-generic i686
NonfreeKernelModules: nvidia
AddonCompatCheckDisabled: False
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.23-0ubuntu4
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: valmir 1445 F.... pulseaudio
 /dev/snd/pcmC0D0p: valmir 1445 F...m pulseaudio
BuildID: 20111228084953
CRDA: Error: [Errno 2] Arquivo ou diretório não encontrado
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xe6000000 irq 41'
   Mixer name : 'Realtek ALC888'
   Components : 'HDA:10ec0888,1458e601,00100001'
   Controls : 40
   Simple ctrls : 22
Channel: release
Date: Wed Feb 1 23:17:34 2012
ForcedLayersAccel: False
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111012)
IpRoute:
 default via 192.168.2.1 dev ra0 proto static
 169.254.0.0/16 dev ra0 scope link metric 1000
 192.168.2.0/24 dev ra0 proto kernel scope link src 192.168.2.103 metric 2
Profiles: Profile0 (Default) - LastVersion=9.0.1/20111228084953 (Running)
RfKill:

RunningIncompatibleAddons: False
SourcePackage: firefox
UpgradeStatus: Upgraded to oneiric on 2012-01-31 (2 days ago)
dmi.bios.date: 10/08/2007
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F5
dmi.board.name: 945GCMX-S2
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF5:bd10/08/2007:svnGigabyteTechnologyCo.,Ltd.:pn945GCMX-S2:pvr:rvnGigabyteTechnologyCo.,Ltd.:rn945GCMX-S2:rvr:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: 945GCMX-S2
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Launchpad Janitor (janitor)]

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

[Christoph Werthwein (krissel)]

I'm experiencing the same behaviour on 12.04 since the latest batch of updates. I think it exculsively happens on sites using Flash.
The browser hangs for some seconds and sometimes the flash plugin crashes. Reloading a page solves the problem most of the time.