Windows 7: uncommon? dual display image quality issue

1. I used windows xp on exactly this hardware setup and it was fine.
2. I have 2 displays 20 inch(1600x1200) dell set up vertical and 30 inch(2560x1600) dell horizontal, they're set up in expand desktop(dunno the exact english name) mode.
3. while watching veetle(800kb quality, so decent) on my big screen i get huge pixels, there's no smoothing at all, on vertical screen it's ok and when i switched my big screen to vertical it was ok also(when i switch my smaller screen horizontal it gets bad...), when you move stream window in the middle half the image is good, half is bad
4. i tried a lot of drivers, even over one year old, no change, clean windows install had the same problem, tried a lot of nvidia settings
5. so do you have any clue what might it be?

How do you have the displays connected? You're not using VGA, or VGI>DVI adapters?

30 inch is dual dvi and 20 is hdmi->dvi adapter, i have gtx260 forgot to mention,
this setup is exactly the same as on previous sytem where it worked fine, so it's like 100% software problem imo and since i tried at least five different drivers i also excluded driver problems so windows is what's left

Yeah you're right, I just wanted to be sure you didn't maybe make a change to the display hardware.

Have you tried viewing a high quality video (local video/video disc) using say Cyberlink, or even WMP or VLC? Can you see the same noise in the image, or only when streaming?

I've seen similar issues but you're not using old VGA junk

Windows 7 is certainly capable as well as the GTX260. Great Gpu for its time, and packs the necessary goods in the driver package as well. There are others here who may have more experience or have seen this before, msyelf I've only seen it as result of a hardware issue, straight forward.

local video is fine on MPC-HC which is what i use it's only veetle, other streams like zonein(it's flash?) are ok, youtube is ok
i guess what matters is that when any of my screens is vertical the picture on it is smooth and when horizontal there are big pixels.

No doubt fixable. I'll msg an editor I know, he works in Eyefinity and does tons of production, I'll see what he says. He's used Nv in the past.

In the meantime hopefully someone else can chime in, there are many experts here. Just a matter of them seeing the topic.

EDIT: Also, have a look at the advanced video settings for Veetle. Look for settings/features related to your specific setup, that you can adjust. Also if there's any options for using hardware accelleration make sure it's enabled. (I have no experience with this program at all, or any Streaming services for that matter)

Also, just as a note. I'm very curious whether even a 800kbs stream is anywhere near what might be necessary to get good quality across such a wide viewing space. In other words, can that particular quality of stream look normal across sooo many pixels. Well wait, if youtube and others with similar quality look fine, this may actually come down to the driver. I'm just not familiar with Nv Control Panel any longer, been ages. I'd try fooling around with video settings or at least looking them over for something that may be relevant.