Dont' know what exactly you're doing to the .raceconfigxml file so I don't what to tell you there.  If you're not playing Metaverse games, you can simply edit the CustomPlanets.xml file to set up your home solar system however you want.  Better not to mangle the original file though.  Copy the file to a mods directory, point to the directory in the game options, and enable mods.  If you are playing Metaverse, I wouldn't go further than setting my homestar to Thalis in the .raceconfigxml file.  If you do that, don't play with the Thalans enabled or the game will have two homestars with the same internal name.  It's not designed to do that and may be the cause of the wierd behavior you're seeing.

Precursor mines and libraries rarely show up on a home planet, but it depends on how many habitable planets you're playing with.  There's typically only one each of those 800% bonus tiles in the whole of the game.  The 300% tiles are much easier to score using Ctrl-N.  You should see a few of those in 40 starts, but it's possible to not see any.

Yea, Ctrl-N goes wonky sometimes.  It doesn't happen often, but I've had it lock up the game before.  Other times I've seen it to set intelligence on one or more of the races to "fool".  I would probably just chalk it up to that and forget about it if it's not happening all the time.

Yea, that's likely it has.  I haven't seen it for a while and I don't always keep up on that sort of thing.  In any case, I've only seen it happen once or twice myself.

Aruno, did you use the instructions in the Kzinti-forum at the Core for the ARC?

I used them at one time, too; and got the same results -  judging from what you wrote "Thalia II II, Thalia II III and so on" I think the ARC didn´t work, because the description at the Core gives the wrong filepath.

Jack once told me that any ARC in ToA will trip a flag - however, the only thing you can do is (and I think you have done so) is to change the name of your homestar in-game - which will then give you a second planet - but it´s not the Thalian original system with which you play then. (The homestar name was different, correct?)

Yes, correct, but how do you explain the different names of your planets? In the Thalian system planets are named "Thala", "Thalia II", "Thalia III" etc and homestar "Thalis". There´s no "Thalia II II" or "Thalia II III"; as well as the PQ is fix, it doesn´t change... (anyway, it did change to the better to you, so nevermind....)

After following those instructions I had the same results - changing the homestar-tag in the .raceconfig-file @ the MyGames-folder to "Thalia II" will give you a system where planets are named "Thalia II II", "Thalia II III" etc, but observe the homestar is not "Thalis" but "Thalia II".

And later, the in-game changing of the homeworld-field to a world that does already exist in an original system will do the trick of giving you this extra planet - but that´s a thing that can be done in DL it´s not ARC.

Well, later on I´ve been told that ARC happens with the raceconfig.xml in the applications installation-folder, and NOT in the MyGames folder, but I didn´t pursue this anymore because my game did trip a flag (it´s been a ZYW submitted too early...)

But anyway I'm  curious how you managed to get this PQ 19? On what raceconfig did you work actually?