The pilot of VH-TJL reported ready at the holding point for runway 23, and was cleared for take-off. He had noticed the landing lights of Singapore Airlines SIA227 on a 7 mile final and queried the clearance. The air traffic controller confirmed that he was cleared for an immediate take-off. As VH-TJL commenced to roll, SIA227, which was now on a 2.5 mile final at approximately 600 feet, was cleared to land, but the pilot elected to make a missed approach and commenced a go-around. In the air traffic controller's opinion an unsafe situation could develop if VH-TJL climbed up towards the overflying Boeing 747, so cancelled its take-off clearance. The take-off was rejected from below V1 speed, and after completing checklist procedures the aircraft taxied from the runway. Garuda Airlines GIA227 on a 3 mile final was cleared to land, but also went around. Pre-dawn conditions existed at the airport with light and variable winds on the ground, but aircraft reported strong south-easterly winds with moderate to severe turbulence above 500 feet which may have allowed a faster than normal final approach. A CAA investigation with supporting information, found that a breakdown in separation standards had not occurred, and runway separation standards would have been maintained if either aircraft had continued its approach for landing.