Re: Tearing on TVout with 8500GT
this sounds like a refresh rate issue.
i would find out what the refresh rate of the monitor is and match it to the refresh in your xorg.conf.
there are some additional things you can do to improve quality if you are doing an analog output, for example, to svideo. they are fairly well documented in the driver readme (not telling you that to be rude, or anything, it's just been a while since i messed with it)
like i said, though, my bets are on refresh rate, or maybe configuration of the application that is playing video.