Looks like ATI card problem again. This happen to me too. To partially fix that I just turn off anisotropic filtering in ATI catalyst center. But this is annoying anyway.
Thank you. I did search a bit but didn't find that thread.
Yes, I do have an ATI/AMD card and for some reason Catalyst was indeed forcing anistrophic filtering for all applications. After setting it to "application controlled" the problem went away.