ROBBEN ISLAND—Following reports he crossed international borders without first calling his parole officer, former South African president Nelson Mandela celebrated his 94th birthday yesterday in a Robben Island prison cell. "It's unfortunate when this sort of thing happens, especially since Nelson's usually so good about the weekly phone calls, drug tests, and not associating with other ex-cons," said Mandela's longtime parole officer, Ted Jackson, who claimed that despite successfully holding down a job as an international dignitary for the past 22 years, the former president is still "held to the same standards as all former inmates." "He's been warned before. Hopefully, this will teach him to call me next time he plans to leave for another overseas conference on international poverty." Mandela previously violated his parole in 1993, after failing to make a court appearance while he was receiving his Nobel Peace Prize.