I don't have the HNP so I can't comment sorry.
And it didn't work anyway: I changed to interstate postcode 3000 (which worked) then tried again my capital city (5000) and still the same S03 :( And yet, it still accepts my local 5xxx code (with wrong clock).
And btw the clock is exactly the same on postcode 3000 (off by half hour) so maybe 5000 wouldn't have fixed it anyway.
The curious thing is as it's connecting during guided setup with postcode 5000 the "loading info" gets all the way to about 75% and then suddenly S03's.
edit: tried a few other 5xxx postcodes around the CBD, none of which work. And yet my local 5xxx postcode which is a lot further from the CBD does work. btw the white debug "print to screen" text reports dial code 140 before I'm trying to connect.
Guess the only thing left to try now is leave it unplugged for 2.5 days until guide data runs out then try again.
edit 2: one curious thing I did notice is the dial code shows 140 in the system info page but shows 000 on the screen where you enter it. Maybe I need to enter 140 in there as well.