GeForce GTX 660
Short description of error
With Blender 2.79a using the hard cut (Sh+K) in a movie clip is not working correctly. The right side of clip, after the hard cut, has a different "dimmed" color and if you try to play the clip (Alt+A) after the cut, there is a frozen image.
I downloaded and installed Blender 2.79 and the problem disappeared. So this bug was introduced in Blender 2.79a.
Exact steps for others to reproduce the error
Select movie clip
Play clip through the cut (Alt+A)