I note that Qantas are apparently conducting "scheduled maintenance" so strange things may be occurring, but looking at my account, I notice that all the reference dates have disappeared from my DSC's. Currently, I'm only owed 40 DSC's and I'm carefully tracking to see if they appear, but without reference dates, it becomes very hard to establish one's claim eight weeks after the flight.
With reference to the GV business angle, if people purchase a GV, they are locking themselves into a future Qantas flight. There may be DSC implications but I would have thought that ten purchases of $50 GV's, and consequently ten future flights, is better than one purchase of a $500 flight. Obviously the purchase of ten $500 flights would be ideal but when people have limited funds to splash out, or are uncertain as to their exact travel plans, surely it's desirable to lock them in for the rest of the year?