fullscreen flash video is choppy and takes 100% CPU

[binary.koala]

Jaunty LiveCD,
when played fullscreen Flash videos (youtube) become choppy, video stops for a second every 2-3 seconds, CPU load is nearly 100%. Same result on installed and updated Jaunty and Jaunty LiveCD (http://cdimage.ubuntu.com/daily/20090321 ).
Situation _worsens_ with compiz turned off (no desktop effects) as it seems to resolve the problem by dropping video frames instead of jerking up. Since I'm not using desktop environments the problem is more evident to me.
Same system Intrepid LiveCD - cpu load 20-30%, no stops.

Tasks: 112 total, 6 running, 106 sleeping, 0 stopped, 0 zombie
top - 03:30:18 up 31 min, 4 users, load average: 1.19, 0.85, 0.53
Tasks: 112 total, 4 running, 108 sleeping, 0 stopped, 0 zombie
Cpu(s): 77.8%us, 1.7%sy, 0.0%ni, 20.6%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 1987428k total, 601692k used, 1385736k free, 35328k buffers
Swap: 3437868k total, 0k used, 3437868k free, 328992k cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 3909 root 20 0 357m 41m 16m R 96 2.1 4:31.52 Xorg
 4153 danja 20 0 303m 131m 33m R 62 6.8 7:48.59 firefox

$ lsb_release -rd
Description: Ubuntu jaunty (development branch)
Release: 9.04

$ uname -a
Linux www 2.6.28-8-generic #28-Ubuntu SMP Thu Mar 5 21:49:36 UTC 2009 i686 GNU/Linux

$ lspci
00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07)
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
00:03.0 Communication controller: Intel Corporation Mobile 4 Series Chipset MEI Controller (rev 07)
00:19.0 Ethernet controller: Intel Corporation 82567LM Gigabit Network Connection (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 03)
00:1a.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 (rev 03)
00:1c.3 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 4 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 93)
00:1f.0 ISA bridge: Intel Corporation ICH9M-E LPC Interface Controller (rev 03)
00:1f.2 IDE interface: Intel Corporation ICH9M/M-E 2 port SATA IDE Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 03)
03:00.0 Ethernet controller: Atheros Communications Inc. AR242x 802.11abg Wireless PCI Express Adapter (rev 01)

$ aptitude show xserver-xorg-video-intel
Package: xserver-xorg-video-intel
State: installed
Automatically installed: no
Version: 2:2.6.99.1+git20090319.bedc894a-0ubuntu0tormod

$ aptitude show xorg
Package: xorg
State: installed
Automatically installed: no
Version: 1:7.4~5ubuntu16

$ aptitude show flashplugin-nonfree
Package: flashplugin-nonfree
State: installed
Automatically installed: no
Version: 10.0.22.87ubuntu1

[calisun (nospam4me-excite)]

I have exact same problem on All FoxNews.com videos, it is very choppy ether on small windows or full screen.
For me youtube works ok, but the FoxNews videos are very..very bad.

[Øyvind Stegard (oyvindstegard)]

Same problem here. Fullscreen Flash in Ubuntu Jaunty beta is worse than ever, even on Nvidia with proprietary driver. If I move mouse cursor while a Flash movie is playing in fullscreen, the video stops completely and drops frames like mad. I see the same problem on different computers, all running Jaunty beta.

[DanielRoesler (diafygi)]

I can confirm that this is still present in Jaunty final release.

[raymano (rezgol)]

I am experiencing the exact same behavior on Jaunty final updated with latest. This is my graphics card:

00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)

[felixcorrales (felixcorrales-yahoo)]

This is a similar bug report:

https://bugs.launchpad.net/ubuntu/+bug/346289