Well it looks like they've got the schedule up on the website now at http://australianairlines.com.au/schedules.html , though only one flight a week at the moment.

Sydney Sabah 1015 1555 Sun AO 7863 29 June to 20 July 03S
Sydney Sabah 1015 1540 Thu AO 7863 From 31 July 03
Sabah Singapore 1645 1855 Thu AO 7863 From 31 July 03

And return:

Sabah Sydney 0615 1510 Mon AO 7864 29 June 03 to 21 July 03
Singapore Sabah 1915 2120 Wed AO 7864 From 30 July 03
Sabah Sydney 2230 0730+1 Wed AO 7864 From 30 July 03