Never seen that before. But you guys down under get different motors than us folks here in the States.
I swapped the direction of my motor a long time ago (there's instructions on how to do this here in the Forum), so the main part of the rod wouldn't unscrew. I've also tried to use LokTite on most of the connections so they don't come apart. Not sure what happened this time, but I'm going to apply some more LokTite to it, just make sure!