I came across a serious stutter issue which I can reproduce easily as it makes the movie unwatchable due to constant stuttering (video+audio). It happens only when playing BD with Menu processing (not when playing without) and Audio is set to LPCM 2-channel output (not when set to RAW). The actual audio track apparently causing the problem is "2-channel DTS HD 48Khz" (as typical present on many recent re-mastered older movies). Can be reproduced using both X9S and Z9S running the most recent FW's. Most likely all other Zidoo players have this problem too.