The Witcher: Enhanced Edition cut scenes do not display properly
- Setting lighting settings to low is actually the best working 'fix'.
Others include
- setting the game's executable compatibility mode to Windows Vista, and
- updating your video card drivers (Nvidia / AMD).
These don't seem to work for everyone, however.
sources:
several Steam threads (1, 2, 3, 4)
on the CD Projekt Red fora there is no mention of a fix (1, 2)