IT WORKED IN PREVIEW - WHY DOESN'T IT WORK NOW?!	:(
--when you build + burn your disc, DVDSP prompts you to select a folder, where it will write your disc image prior to burning. You should make a new folder, or at least make sure the folder you are using is completely empty before you start building the disc. Otherwise you risk burning files to your disc which do not meet the DVD specification, and are thus 'not allowed'. --make sure you have set a valid 'startup action' in your disc's property manager. Whether you want your disc to begin with your main menu, or a slate, or your first video track, make sure this item appears in the 'startup action' line. --Make sure your region code is set properly in DVDSP's disc property manager - to either 'all regions' or the region specific to your DVD player. --If you have done all of the above, simply try to burn it again, or use different DVD-R media. It could just be a case of a bad burn or a media brand which is incompatible with your player.
VERSION: N/A AND ALSO... SOURCE: Jon Lottman