curves, levels box gone black in 7.0

When I start 7.0 (as of 3 days ago) the box in mid-screen that usually had names in it is totally black as also are my curves and levels boxes. I can still see the levels sliders and can still adjust the picture but cannot see the histogram because the box is totally black. All was fine. Can anyone help.

sounds like a video driver problem. check for updates.