I noticed a problem with the Qantas computers in that regard last week. When I flew SYD-SFO, my boarding pass said Sapphire, and I have not held that status since the first half of 2002. I presented my AA card with Emerald on it, and they corrected it in the computer, and allowed me access to the F lounge.

When I was in the boarding area for the flight, I overheard another passenger talking about her Sapphire status being incorrectly recorded on her boarding pass as Ruby.

I don't know how widespread these problems are (status displaying incorrectly), but was glad I had my card with me.