DVI/HDMI Monitoring is a smart solution and has a lot of benefits (e.G. GPU processed video can send directy out to the monitor) but also has drawbacks becaus sometimes you are at risk of occasionally stuttering (SDI framebuffer cards are more stable at this currently) and you have to set the screen refresh rate for yourself (50Hz, 59,976Hz, 60Hz, 48Hz...)
--> Video tearing is a thing that should not occour on a modern computer with a GTX 460.
Do you also have video tearing with VLC media player or Windows Media Player?
--> You have to check you Video driver settings to get rid of the tearing I think...
I don't have any video tearing with my Nvidia Cards exept one really old 8400GS in a server...