I agree, it is the German exchanges so far bringing up the stock...

I agree, it is the German exchanges so far bringing up the stock price. So the cycle I see is ASX -> Frankfurt -> OTC and then repeat. Whatever the price in Euros closed at the night before is where the OTC market picks back up, etc. It's usually easy to see what it's going to open around and I'm sure any trades in the queue will have an effect.

I like the ADR for short-term investing, but I have mixed feelings about it. The pros are no $50 foreign exchange fee and I believe they don't allow short-selling. The cons are that it's a higher price per share (since it's a 40-share bundle) and for some reason, I feel psychologically more inclined to buy 40 $1 stocks than 1 $40 stock (maybe that's just me). Also, one doesn't own the underlying share of the ADR and have the same benefits as an ordinary stockholder.

I think the ADR is going to be more appealing to short-term traders (in smaller volumes) and institutions when there is significant interest (as you noted).