I recently installed Premiere Pro CS3, and found, like many others, that after importing a video file with AC3 sound, the sound was not actually imported at all. It seems that Adobe omitted a very important file from the Premiere installer. The file name is ad2ac3dec.dll, and can be found in Encore CS3 if you have that app installed. Just copy the file from the Encore install folder to the Premiere install folder and everything works well. For those that do not have Encore installed and want the above-mentioned file, contact me and I'll get it to you somehow.