Do continent rules differ between ex-SWP or ex-Asia DONE4s?

Background - historically I have bought my DONEs ex-MEL. Given the current USD/AUD rate that is no longer attractive. So I want to buy it ex-BKK. But what I want to do is the following:

BKK-MEL-LHR-....BKK

Now i know there is usually an exception to the 1 only arrival/departure for each continent for Asia where in transit between SWP and Europe. Does this exception still apply for tickets ex-Asia and thus would the above itinerary be valid?

[This message has been edited by alect (edited Feb 12, 2004).]