A Brussels Airlines Airbus A330-300, registration OO-SFO performing flight SN-241 from Monrovia (Liberia) to Brussels (Belgium), was enroute at FL400 about 130nm southsouthwest of Basel/Mulhouse (Switzerland/France) when the crew received a left hand cabin ventilation fault message shortly followed by smoke and a burning odour on board. The crew decided to divert to Basel for a safe landing about 28 minutes after leaving FL400. The aircraft was able to continue the journey after 2.5 hours on the ground and reached Brussels with a delay of 2:20 hours. The aircraft is still on the ground in Brussels about 10 hours after landing in Brussels.