I've been having problems with the duplex release also. Problems consisted of audio being out of sync audio with subtitles, lagging (10 sec freezes) after completing battles and lagging or temp freezes opening the book. Never completely frozen my system were I needed to hard boot my ps3.
using mM, external 2TB WD 5400rpm, BD Mirror turned OFF, Rebug 4.30.1, and default game settings. I been playing a while and it never complete froze and the lacking sometimes and freezes after battle are annoying but I been dealing with it.
(Just sharing my experience)