I had turned the glyphs of a ttf-font by 90 degrees but the program that I used left the embedded bitmaps in the EBDT tables of the font unrotated. Using this font for example with Word had the interesting result that the font sometimes showed up correctly and sometimes not, depending on the size of the text on the screen.
Interestingly enough, using the same font as an embedded font with Adobe Digital Editions 1.6 the font showed always up correctly on all sizes of the text.
For me this looks as if Adobe Digital Editions does currently not support embedded bitmaps in ttf - fontfiles.
Anybody had the same experience or knows about an official statement from Adobe concerning this?