Update: Well, I split the PNR for my party of three into 2 (wife and daughter) and 1 (myself). I get the new confirmation number. The wife and daughter stay under the old PNR. Even as Golds, conventional wisdom tells us that this should improve the chances of someone getting EUA'd. On the leg over, the wife and daughter get EUA'd. I sit back in economy. OK, I figure it was a crowded flight and they probably had just two open seats in First left when our turn to upgrade rolled around.

Time for the two return legs, and I check on the upgrades. Both wife and daughter are again EUA'd and I'm still in economy. Again? A call to the NW Gold elite line, and I find out that splitting the PNR has evidently caused the EUA computer in some glitchy way (I was concurrently assigned multiple entries/information of both the old and new PNRs) to continually skip me. It appears that there were enough open seats for all three of us to get EUA'd, but now they've gone to the Silvers. All gone.

No sour grapes here. Splitting the PNR was the right choice, and I would do it again. The moral of the story is that we probably shouldn't depend on the system taking care of itself. I don't know if the agent who gave me the PNR failed to remove all the old information, or it was purely a computer glitch. (They are looking into it.) I realize now that I should have confirmed that everything was in order with a different agent after I had the PNR split, and then checked on the status of our upgrades previous to the 24 hour check-in. Lesson learned.

Anyway, can't really complain about getting 2/3 of the upgrades. Of course I'll let the wife and daughter enjoy First. I've still got my bulkhead aisle seat.