Looking at the specifications at the Vio site, your camera records in H264 video with AAC audio. Some newer dvd players have the ability to playback mp4 using these codecs, but obviously not all.
The simplest solution is to convert to dvd-video.
There are many varieties of resolution/frame rate available using this camera system. Do you know which combination you are using for your videos now? This does make a difference, as some of the higher framerates might prove to be difficult to convert. You can use a program called MediaInfo to find out what is in them (I find the Tree view within MediaInfo to be the most informative), and then post the results in this thread. Be careful not to install any "extras" that are offered when installing MediaInfo.
You can try a free program called AVStoDVD to convert your mp4 files to dvd-video. There is a guide for setting it up and using it in my signature. If you have problems converting with AVStoDVD, there is a commercial program called ConvertXtoDVD that will probably work for this.