Personal security - South Africa

I'm interested in getting a clear picture about personal safety in SA.
I intend in skipping Joburg but will be in CT and Durban and the
smaller cities and villages along the coast. How safe are these
places? Is it true not to walk/drive after dark?
Are the stories exagerated or should I really give the country a skip?
My plan is for a 2-3 week trip in Mar-Apr 2004.

Thanks.