WGL_ARB_pixelformat is gotta crasy!

So, my problem:
I wrote a small prog that tries to initialize the pixel format of the window using WGL_ARB_pixelformat extension. And, at the and I got 16 fps performance!!! and this simply clearing the screen(200x200) and swapping the back buffer.

My system:
Duron 1200, 128 Mb RAM, GeForce3 200 with 128 Mb RAM

But than I tried to do the same using standart pixel format techniques(ChoosePixelFormat etc) and: 3000 fps!

In both cases it run under fuul acceleration! What can be the case?

P.S. The case is clearly SwapBuffers, because if I am commenting it, I come at 8000. But???

Got the bitch: it was ****in swap interval…