Hi Drake,
Do you have any Add-on Airport scenery installed .... example CLS Pro Sydney??? .....if so ...unistall the scenery software, run Fltsim again so it can rebuild it scenery database and try re-installing the software again.
Then again,
Is there any another AFD.BLG files added the scenery files near YSSY ...ex...bankstown,richmond or Camden ...this sometimes can cause issue like this....
What happens when you fly around YSSY airspace on a different aircraft???????
Marco