Welcome to the forums dossrodsr.
May I ask, exactly what it is you are doing? ConvertXtoDVD is a program designed to convert various types of video files to dvd format. I haven’t heard of anything called VSO Convert4x.
If this is in fact ConvertXtoDVD, have you tried making the program output to the hard drive, and then burning the dvd-video with ImgBurn? ImgBurn is a free burning program, and easily the best available.
Also, the free version of ConvertX will put a watermark in the video that is not removable. If you want a free alternative that produces higher quality dvd-video let me know.