In response to the query about Marlon Riggs and the representation of
African Americans in the media:
I saw a Riggs documentary about a year ago called "Color Adjustment"--or
at least that's the title i seem to recall.  The documentary dealt with
the representation of blacks on television.  Not only did it critique
the more overtly racist TV images, but it called into question the whole
notion of "positive" images.
  if i recall, the film touched
on "The Cosby Show" but was made before shows such as "In Living Color,"
"Roc," "Martin," "Living Single," etc.