i have a sony nwz a818 video walkman. it should be drop and drag for song and video files. songs transfer fine but some video files when played have the sound about one second behind the picture for that entrie file. i have used a free program called xilisoft mp4 converter to convert original video files. do you know of any other free, or payable software, which will convert video files to a walkman format. The walkman manual reads: file extension .mp4, .m4v codec avc, mpeg-4, frame rate 30 fps and resolution max QVGA 320x240.