In case you don't know what screen tearing is:
http://en.wikipedia.org/wiki/Page_tearing
There is a way to force vsync with nVidia drivers but the results were not reliable and only worked with nVidia cards.
Never did figure out how to force vsync on my Asus/Intel 82g33 system, till now!
Had no luck with xorg.conf but I finally found the ticket:
DRICONF
http://dri.freedesktop.org/wiki/DriConf
My package manager "Spritz" did all the hard work and found a DriConf package.
No more screen tearing!!!!
Whooo Hoooooo!