pcechan

I just installed the free version for Prism Video converter. When I tried to replay a video file from added list, I found that there is no sound for mp4 files but ok with wmv or mpeg files. I also found same problem with vob files. I tried to open one track in a DVD (vob file), the Prism shows the video but no sound. Anyone encounter such problem with the free version? I tried to convert a vob file to wmv file. The converted file is again only video without sound.