Try to trim audio and video at once, in the exact same position(when you 'split' the track, both video and audio should be split at same button push). They should stay together, but if they don't, then 'zoom' in on the track and be sure to realign them to the exact frame. If you re-render the newly cut section to a new .avi, the sound should be saved in the .avi too. (in other words, you shouldn't need to save a separate .W64 file.) If you want to save separate files, then you may need to align them each time you bring them in. (try auto-ripple, maybe this will drag it after it's been aligned.) Another way is to just 'loop'(instead of trimming) the section you want to save, and re-render a new .avi of the looped section. The sound should automatically be rendered as a .wav and be brought back into the timeline and drag together with the video. This is how I rerender sections. In my experience, once the video and audio move separately, it stays that way. Usually somebody corrects me soon after I post, if I'm wrong.