You should move down-under mate - better skies, same crappy politicians. Warmer too!

Anyway, just quickly tested my K-3II - with the GPS off, if I then enable GPS logging it'll override it and turn on the GPS as well (makes sense...). If I then turn logging off, the GPS returns to the off state. That matches what you are saying, so maybe this is the underlying issue?

Ok, in the GPS menu section, make sure that under Additional Settings you have the Indicator Lamp enabled, that will cause the orange light to come on when the GPS is. Exit the menus and turn on the GPS with the physical button - orange light should come on and you'll have a red satellite icon on the rear LCD as it attempts to locate the GPS signals. Don't worry about leaving the GPS on all the time, it sleeps when the camera does, and will spring back to life when you half press the shutter button - ends up being very battery friendly (I have gotten 1,000 shots on a single charge with the GPS on, but that was with the rear screen off).

Fingers crossed the problem was something as simple (and frustrating) as that.

Yeah, y'see that "seems sensible" rule for logging automatically turning GPS on was my downfall. Since Astrotracer ALSO requires GPS, kind of thought the same rules would apply.

Nope.

Well, it does seem quite sensible! And that is where we went wrong

Just like the manual. Knowing what I know now, through experience, I can understand what it is telling me, and I know it does actually set it out. The problem is it seems to have been written assuming the reader already knows how to use the astrotracer - when I started out, knowing nothing, it was near useless beyond telling me to do the precise calibration.

Being able to turn astrotracer on, without turning ON the GPS that it needs to work...what is the point of that?

Still cloudy...sunny days, cloudy nights. Driving me mad!

seems to be an oxymoron! reckon the astrotracer screen is rather generic in that manner........but a good question!

Turned on the weather man just after the news
I needed sweet rain to wash away my blues
He looked at the chart but he look in vain
Heavy cloud but no rain

Back in time with Louis XVI
At the court of the people he was number one
He'd be the bluest blood they'd ever seen
When the king said hi to the guillotine
The royal astrologer was run out of breath
He thought that maybe the rain would postpone his death
He look in sky but he look in vain
Heavy cloud but no rain

Well the land was cracking and the river was dry
All the crops were dying when they ought to be high
So to save his farm from the banker's draft
The farmer took out a book on some old witchcraft
He made a spell and a potion on a midsummer's night
He killed a brindled calf in the pale moonlight
He prayed to the sky but he prayed in vain
Heavy cloud but no rain

Heavy cloud but no rain
The sun won't shine till the clouds are gone
The clouds won't go till their work is done
And every morning you'll hear me pray
If only it would rain today

I asked my baby if there'd be some way
She said she'd save her love for a rainy day
I look in the sky but I look in vain
Heavy cloud but no rain

I've had a Pentax camera since Christmas last
Taken shots of some stars and it's been a blast
But I'm having some troubles with the GPS
So I need to get out and run some night-time tests
So I pack it all up with firm resolution
To get far away from the light pollution
Look to the sky, but I look in vain
Heavy cloud but no rain.

Looks to me like a calibration issue. I had similar issues when I tested the K-3 II at first. The calibration on it is SUPER sensitive to errors. I found that I was better able to calibrate the O-GPS on my K-3 than the K-3 II unit. The rotational axis for calibration needs to be the sensor's center, and that's hard to achieve. In general, I found that the O-GPS delivered better results than the K-3 II for me, in general. I also found that the K-3II was less accurate the further away I pointed it from north. This was also true of the K-3 with the O-GPS, but to a significantly lesser degree.

I suspect (no evidence for this) that when the GPS was moved inside the camera either something in the hardware changed or the software was not updated to address the unit's changed location. And while a couple inches might not seem like a world of difference (if the software was in fact not updated to reflect that changed location) in the world of 24mm-wide sensors, a 50mm-triangulation point change would be significant.