Click on this icon in the build mode and the created image will be saved to your hard disk, instead of being burned directly.
Can you post the full log of the failed burn attempt? You find it here: Main Menu -> Help -> ImgBurn Logs
If you have a RW disc, try with that one so you don't waste any discs during your runs. When you know it works - switch to regular discs. It will be less expensive for you.