Hello,
This is my first post on BT forums, I hope it will solve this old problem. 
So, I had the same problem and I managed to solve it by updating the Xorg display driver for intel adapters (namely xserver-xorg-video-intel package and its dependencies).
The hardware and software used for implementing & testing this: Lenovo Thinkpad T420, Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz, with new generation display adapter from Intel(listed by lspci as "00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)"). I am using Backtrack 5 R2 64bit as OS.
The xserver-xorg-video-intel upgrade procedure I took from this thread: http://ubuntuforums.org/showthread.php?t=1484137
(see the first post of the user named "rlzaleski" ..)
The commands (which obviously must be executed as root) are:
Code:
# add-apt-repository ppa:glasen/intel-driver
# apt-get update
# apt-get upgrade
After the above commands are successfully executed, restart the X server or reboot the whole system.
Next time when X starts, the difference should be visible: desktop effects are working like a charm, videos play smoothly in fullscreen, and glxgears fps reports should be significantly higher than before the upgrade. 
Here are the outputs in my case, before/after upgrade.
Before:
Code:
# glxgears
912 frames in 5.0 seconds
962 frames in 5.0 seconds
928 frames in 5.0 seconds
948 frames in 5.0 seconds
970 frames in 5.0 seconds
...and after:
Code:
# glxgears
13313 frames in 5.0 seconds
13937 frames in 5.0 seconds
13931 frames in 5.0 seconds
13803 frames in 5.0 seconds
13811 frames in 5.0 seconds
15223 frames in 5.0 seconds
NOTE: if you don't have glxgears command, install "mesa-utils" package.
So, this upgrade worked in my case. Hope it helps others with similar problem.
If this works for anybody else, please write here a short confirmation.