I'm assuming that most people (in the UK, at least), saw the English language version of this film that was broadcast on UK TV (Channel 4). In which case some of the other comments posted here are pretty astute - especially those referring to the voice-over as sounding 'like an actress reading from a script' and 'not speaking from the heart as a real person'.
Well ... I produced this film and so I'm happy to shed some light on this here. In the English- speaking version, it WAS an actress and this WAS a flaw ... but the words were not scripted. In the original French language/English subtitled version, the words were spoken by the very real woman you see on screen ... they were all her own words and it is a far, far more powerful piece because of it. Unfortunately, the broadcaster was not happy about transmitting a subtitled version so we had to draft in an actress at the last minute to dub the dialogue ... a fact that neither I nor, I can assure you, the director, Kapwani Kiwanga, were in any way happy about.
The French/subtitled version has since had a life of its own playing in festivals around the world and has even won the Venus De Badelona award for Best Documentary in Barcelona in 2005. It will also be screened on Canadian TV this year (2006) in its original version. If anyone reading here has seen the dubbed version and would like to see a version of the film as the filmmaker intended then I would be happy to send you a DVD if you send me your address.