Major Description
The extracted TTF fonts generated by TTFSubFont do not conform to the TrueType standard.
Most notably, the font checksum is calculated to an invalid value
among other more subtle issues. Users may experience a screwed up firmware of Minolta printers when such a file is printed via Adobe Reader and the Windows PostScript printer driver.
With the help of Microsoft's font validator tool, I have already been able to
fix most of these problems in my original code:
http://www.microsoft.com/typography/fontvalidator.mspx
A port of my patch to pdfbox is on the way, but it's quite cumbersome to port the patch to the pdfbox code. (tab vs. space, testcases needed...)