You can try to add
psEmbedTrueTypeFonts no
to /etc/xpdf/xpdfrc, but note that it can cause font problems with other documents. This is only a workaround, not a fix.
Another possibility is that the bug is in font embedding done by pdftops.
You can try to add
psEmbedTrueType Fonts no
to /etc/xpdf/xpdfrc, but note that it can cause font problems with other documents. This is only a workaround, not a fix.
Another possibility is that the bug is in font embedding done by pdftops.