T410 video issues (tearing, lagging...)

[netrunner]

Hello,
I have T410 with discrete graphics (NVS170M), CPU is i7-620M, 4GB RAM, Win 7 64bit. It is connected to the docking station with external monitor (1920x1200) via DVI.

Now to the problem. When I try to play some HD video (sometimes even 720p!), i can see tearing - doesn't matter, if I use kmplayer, mplayer home cinema or other player. Also it doesn't matter, if I use dxva or not. But i think, that i7-620m has enough power to play HD video itself.
Also when I try to play some older 3D game (such as CS: Source) it is the same - lagging, tearing... Doesn't matter, if I try to play on high or low resolution.

Both problems seems to me like I can see only every second picture.

I have all drivers and software up to date via Lenovo system update and Windows update.

Can anyone help?

Thanks.