Very interesting thread. Nothing seems to be crystal clear. It all gets down to intent. The ATO doesn't seem to have a time frame for the sale and repurchase, but they do seem to have the intent of cracking down on the practise.
Here are a few links that might help the discussion along.
I think the smartest thing you can do is have a trading diary, this would demonstrate your strategy, and help with the analysis of such. It also would be a mighty good weapon in a court of law.