Do you have all the current "patches"? I thought I did but in the Help screen my Key logs for the add on Dolby 2.0 and 5.1 sound was missing and I had to 'repurchase" for about $20
I was having the same problem until last night. I had changed my hard drive and then reloaded Pinnacle 9.1. I could import video from a DVD but no sound... until I purchased 4 or 5 more unlock...