I have had this happen...
Qantas fixed it and gave me the increased status credits a few days later...
I had the following entry into my online statement:
POINTS ADJUSTMENT DUE RECALC OF STATUS BONUS QF 044 ECONOMY 17SEP05 AUCKLAND/SYDNEY 670 670 0
Interestingly for me is that when I flew this flight I wan't a Platinum, but then I sent in some previous boarding passes which I was holding on to (thinking I would keep them until the next year), and when QF credited these points, they worked out that I would have been Platinum when I had taken the flight above, so they gave me the bonus!
Kudos to QF for thinking far beyond what I actually was thinking!
D P G