The JSE (Johannesburg Securities Exchange) is apparently blaming a network fault for the fact that it hasn't yet begun trading today (Monday 14 July)

There have been no SENS (Stock Exchange News Service) announcements, no stock prices and no trades.
The JSE says it is investigating the problem, but couldn't estimate when it would be resolved.
The opening auction has been delayed until the network problem is fixed

* Update: As at 12:00 today (Monday), there was still no news on when the JSE could begin trading. Both the JSE and AltX web sites were still down and there were no SENS feeds available.