Me at SYD Priority checkin (relaxed, polite, smiling): Hi, I'm checking in for QF375 to Port Vila. (booked in Y)
Checkin1 (grim and sullen): You can't check in here, you need to go over to Air Vanuatu checkin.
Me: Yes, I understand this is a codeshare flight with NF11 on the Air Vanuatu plane, but I have checked in at this area for this same flight three times in the last year or so without any problem.
Checkin1: That's impossible. They are on a different computer system. Even if I wanted to check you in here, it physically can't be done. And anyway that flight doesn't open till 2.5 hours before departure so you'll have to wait till then and go over to Air Vanuatu.
Me: Thanks, I'll check back once the flight opens.
---
Me back at SYD Priority checkin (still relaxed etc.): Hi, I'm on QF375 to Port Vila.
Checkin2 (no eye contact, no welcome, no smile, weary, in a loud voice to nearby colleague): What's 375, is that Vietnam?
Me: It's to Vila, Vanuatu.
Checkin3 (puzzled): Oh, not sure, yeah could be Vietnam.
Checkin2 (looking at a printed list, no eye contact): Where did you say you are going?
Me: I'm on QF375 to Port Vila, Vanuatu. You might find it listed as codeshare with NF11.
Checkin2 (grimace to let me know that she's had nothing but know-it-all premium customers all morning): NF11 is operated by Air Vanuatu. You will have to checkin over at their area.
Me: (same story about last three flights).
Checkin2 (another level of annoyance): I'm sorry, you must be mistaken, because for that flight you can only checkin over at Air Vanuatu.
Me: (keeping cool) Oh, I wonder if there has been a change in the system. (But not moving away)
Checkin2 (sigh, loud call to colleague): We can't do Port Vila here can we. It's not on our system is it?
Checkin3: Ah, yeah, I think so, it's on "CM". We can do it here. But he should do it over at Air Vanuatu.
Checkin2 finally gets onto the computer and it's all done. All very stressful it seems, and results in both of us forgetting baggage tags which she has to run after me with.

I guess I should be happy as got Priority labels, 30kg allowance, and Express card, and didn't have to queue. But not an enjoyable experience and I wish checkin agents didn't have this infallible air about them -- two out of the three here were emphatic, but wrong.

Unrelated to this, the poor lady at Immigration desk was quietly sobbing, and when another officer came to start at the next desk he queried her and she said I've been sitting here for four hours straight with no relief and I'm bursting to go to the loo, so he said to her Look, just go, I'll take care of your line, if they ask you when you go past the control desk just tell them you've gotta go. She stamped my passport and headed off wiping away her tears. Amazing. Something very wrong as to how that could ever happen.

And now my next grizzle about codeshare: on boarding, the QF agents carefully set up two lines, putting the usual large Qantas sign pointing economy to the left and business/premium categories etc. to the right, and then announced that boarding was commencing and invited business class passengers to board at the right, and other boarding on the left. After the two bonafide business class pax had boarded (only 4 J seats on the 737), a couple of other Golds and myself in Y went to that line, and were refused admission and sent to the back of the long Y line. I commented that this was contrary to the very clear sign they had put up at the head of the queue. Another snooty response that the line was only for business class passengers.

I know there is lots of fineprint about codeshares using non-QF metal, especially with non-OW carriers, but I think QF could still do more to ensure that:
1. checkin staff are knowledgeable about what their computer systems can and can't do in relation to codeshares (this flight operates on an almost daily basis from SYD to VLI)
2. partner airlines in codeshare with QF allow priority boarding.