On page 3 of http://ftp.jussieu.fr/ftp/pub/tex-archive/macros/latex/exptl/mem/greek.pdf, poppler-cairo shows that it is not able to display the black squares properly (see attached images).
Created attachment 3635 [details] evince black square
Created attachment 3636 [details] gpdf black square
*** This bug has been marked as a duplicate of 3387 ***
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