I copied a chinese font to a font name of mine, and in the private
use area I inserted some special characters, which I generated by
copying existing chars and modifying them.
Now I created two new ones the same way, at U+E011 and U+E012, amidst
other characters I created. The "find problems" function is set to
"set all", and after checking it says "no problems found".
I installed the font both as otf and ttf.
In vim they show up fine, and when I use paps(1), they are correctly
done in the ps output and the pdf conversion with ps2pdf(1).
Now I process my file with xelatex, - and the characters are gone.
Which I don't understand, because the 20 other private-area-characters