I've just moved from SD video to HD now using a Canon HG21. The image quality is excellent even after editing using the provided Image Mixer3 ver 3.2.2 software as no additional compression is applied, however from about five minutes into the video the sound/vision sync starts to go, getting worse the longer the production. I have spent hours testing and trying different options but have come to the conclusion the software has a bug during the save of the production to the finished file. 1. Has anyone else come across this problem and if so is there a known way around it, other than only completing five minute productions. 2. Can anyone recommend a good editing package that works with HD video, I am not looking to compress the data as the picture quailty is important so I want to retain MPEG4 AVCH.264.