Are you trying to save to the same directory that the Puarslitron itself is stored in?
If you are, then that doesn't work due to a quirk with how it does file handling.
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That's really weird because if I remember correctly pretty much nothing is actually different between the two.
According to the devlog I wrote the only thing I changed was the documentation. So if 1.0 works for you then I'd suggest sticking to that.
I'm sorry I can't be more helpful, but as I've said, this was pretty long ago.