When I zoom in on my terrain it goes white: The further in I zoom, the greater the whiteness becomes. Is this normal? Is this to speed up rendering or something? Can I turn it off?

I'm also getting these error messages in the console over and over again:

rc.right != m_GfxWindow->GetWidth() || rc.bottom != m_GfxWindow->GetHeight()

and

GUI Window tries to begin rendering while something else has not finished rendering! Either you have a recursive OnGUI rendering, or previous OnGUI did not clean up properly.

Does this bear any correlation on the issue?

Update I create virtual desktops to flit between using the program Deskpot. Turning this program off and restarting has stopped the above errors appearing in the console. However, I still get white terrain when I zoom in. Not a single error message.

I've restarted my computer to no avail.

I have an Asus NVidia GeForce GTX 760 2GB DDR5 Direct CU II OC Edition Graphics Card. Any known issues?

Update I don't think it's fog...