Extremely Horrible tearing

[Mike.Reiner]

When i try running doom3 w/o verticle sync on, i get HORRIBLE tearing all through out my screen, All i can see is the map, and the models, the hud flickers badly, and overall, its just unplayable.
this only happens in the full version of doom3 for some reason, i downloaded the demo before buying it, because i didnt wan't to buy a game just to find that it doesnt work, the demo ran fine, and then it ran GREAT with vsync off, didnt have the tearing problem, so i went out and bought doom3 full, and when i turn off vsync, i have the problem, il take a screenie of it later on and edit this post with a link of it.
anyone know of what could cause it to happen in full, but not demo?.... *sulk*

btw i have a geforceFX5500 512 mb ram p4 2.4 ghz windowsXP Service Pack 1 Latest Nvidia drivers. (same ones i used to run the doom3 demo)

[0311_Lifer]

i have the same problems but it shouldnt be like this because i set the resolution to 1024x768x32 turn off aa/af etc high details, low detail no matter what i do i get video tearing and herse my specs:

p4 2.8ghz 800mhz fsb h/t enabled
nvidia geforcefx 5900ultra
1gb crucial ddr pc3200 ram 4dimms of 256
antec 420watt truepower psu
winxp home edition sp2
80gb hd

tried latest patch, all new drivers, all those stupid optimisations every one said to do and nothing is helping i get horrible frame rates, i HAVE to enable vsync or theres extreme tearing but when i do disable it the fps jumps and gets ALOT better but it tears alot what the hell is going on with this ?