Welcome to the Forums,
First we are going to need some more information. Please view
This Thread, it provides a guideline to the specific information needed to help you.
This could be caused due to your workflow. While VS is designed and capable of going from the Edit module to the Burn module, using VideoStudio Project files (VSP), several have problems when they do. So an
A Suggested Workflow has been developed to help guide you through the mine-field of video editing, as it pertains to Ulead's VideoStudio Programs. They can be viewed here:
Suggested Workflow for VideoStudio.
This also could be due to the burn speed being used. Most of use a slower burn speed of 4x or 8x max. You might try burning at slower speed.
Then again this could be due to compatibility issues. Your burner may not like the type (brand) of DVD discs. Try using a different brand of disc.
If you're source video clips are of the Hi-Def breed, such as AVCHD there are some slightly different things you need to know. Unfortunately I don't use any, and know very little about them. Ken, and etech do. So it would be helpful if you would post your Video Clip Properties. To do so, right-click on a clip in either the Library or Timeline, select Properties, and post them here..