@sachin: I have tried your test.epub with Sigil, Calibre, Firefox EPUBReader addon, ADE 1.7, ADE 1.8 preview 2, and Nook STR stock reader(RMSDK based). Here are the results:
ADE 1.7: does not show diacritics properly.
Firefox EPUBReader: shows diacritics but the glyphs are slightly different compared to the other readers; also second embedded font displays the same glyphs as the first one.
ADE 1.8p2, Sigil, Calibre, Nook STR: diacritics ok; both embedded fonts seem to be working properly.