Snapersam,
Yep certainly know all about it, the circlip inside the companion shafts does not hold enough tension to keep it locked in under high load situations, there is now a modified companion shaft available to rectify the problem, let me know where you are located, if in Brisbane i can look after it for you, I manage a Mitsubishi service department. cost retails at $700 but will do it for a fellow AF memeber for $600.
Cheers Lee