i downloaded a video from youtube(.flv) which consisted of few parts. i joined them firstly movica but it turned out that only the first part of the video came with audio (sound) and entering 2nd part onward, the joined video just silenced (only picture played). i changed to avidemux later and faced the very same problem to my joined video. before that, a message telling that 'no keyframe found: editing is impossible' came out and when i said YES to repair this, my computer turned hang. the last time i tried (using avidemux) all parts in the joined video were audible but the sounds all turned into 'donald duck' voices... why? Help me plz..