There is a way past this bug. At least it worked for me.
Before clicking on the shuttle on onderon save the game (not quicksave).
Click on the shuttle and watch the cutscene of the shuttle flying to the moon.
The Dxun level will load. As soon as it loads (ie before canderous talks about joining you) hit quicksave.
You will then get the cutscene and the freeze.
Alt-F4 then restart the game and load your quicksave (when i did this i also held the key W down incase the scene was triggered by where you stand. Don't know if that was needed).
The canderous cutscene doesn't play and you can continue.
Atton is grayed out till you reach the ebon hawk then becomes available again.
Only side effect I know was the attack on the palace happened immediately rather than waiting for me to complete another world.
