Hard to say without knowing more about the situation.
What model of camcorder is your video coming from and what format is it? If there is additional audio in your project, what format is it?
When you started your Premiere Elements project, which project settings did you select?
Where did you test-play your DVD? Did you test it by playing it on your TV through a standalone DVD player?
Report back with file details... read below
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037
What is a CODEC... a Primer http://forums.adobe.com/thread/546811
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037
Report back with the codec details of your file, use the programs below... a screen shot works well to SHOW people what you are doing
For Mac http://mediainfo.massanti.com/