Strange result of rendering like grid of squares

When i try to render image i recieve a grid of 8 same squares. It seems like square is a part of render.
Blender version 2.69, Win XP 32, graphic card radeon 9200 with latest catalyst.
BI or cycles is no matter, both of them have same problem.
What could it be?

Thanks in advance!

Screenshots ?
Your render settings ?
An example blend file ?

I’ve found new feature. When i save image it renders good. I have this problem only in viewport of Blender.