in have an xvid file which plays perfect with no errors, but after i have encoded it to MPEG DVD with MAINCONCEPT the playback goes fast and slow fast and slow and so so until it freezes but the audio keeps going, i have done this twice now and get the same results each time, i have encoded other xvid files the same way and have had no problems, the file plays fine before encoding, can someone give me some idea's of why this is happening.