I done a web board search on "Green Lines" and found about 4 pages of possibilities. search.php?st=0&sk=t&sd=d&sr=posts&keywords=green+lines
Could you clarify if you're using Corel Digital Studio 2010, that has VideoStudio 2010, or VideoStudio Pro X3, that comes with VideoStudio 2010 Express? I don't care for either program. Why I ask is, I have searched through my version of VS 2010 Express, and can not find where you can do the following;
1). It could be that you have a wrong setting for Playback in the Preferences. It should be set to Preview Window.
2.) Another possibility is caused by drivers needing updated for a video card. You might check to see if there are any updates for your video card.
3). Don't use VideoStudio 2010, terrible program. Use VideoStudio X3, Advanced Edit not Easy Edit..