After editing the video, try clicking on the Produce tab and make an MPEG. Then create the DVD from that. You will probably have to add the chapters and and menus. Then, try burning to a folder first. If that works, you can use burning software to burn to a disc.
You may also be able to use third party software to 'Shrink' the DVD, but the legality has been challenged in court, so I can't tell you where to download them. They are free, if you can find them.
__________________________________
CORNBLOSSOM