Hello; This is the exact same problem I seem to be having. In Videowave story board each clip at some point audio is distorted. When I open the "trim" window, no distortion. When I open these original downloaded files and view with any video program on my system, no distortion. When I render them to any type of file, the distortion remains. As an aside, when I open MyDVD and use the .dmsm file these clips are in and preview there is NO distortion. Stranger yet, it does NOT happen with each clip whether there are .avi or .mpg which kinda leads me to believe it has something to do with the way these clips were orignally recorded. (We did not record them we are doing a favor for someone and attempting to clean them up and burn them to a blu-ray).
Tiz a puzzlement.
Years ago we had a similar problem with a different version of Roxio and Videowave related to my husband changing recording mode midstream. But in that case, everywhere one viewed the video there was distortion.
As an aside, options of videowave there is a path for audio filters that leads to a folder with no filters; rather some .dat files from my previous projects. The path is c:\users\Kathleen\AppData\Roaming\Roxio\EMC15\VideoUI\AudioFilters
Anyway, in case any of this is helpful to anyone who has the time to help I'm including a few screen shots: