First follow this workflow to help assure the best qualty video DVD:
Once you have the project as you want it save it as a disk image via the File ➙ Save as Disk Image menu option. This will separate the encoding process from the burn process.
To check the encoding mount the disk image, launch DVD Player and play it. If it plays OK with DVD Player the encoding is good.
Then burn to disk with Disk Utility at the slowest speed available (2x-4x) to assure the best burn quality. Always use top quality media: Verbatim, Maxell or Taiyo Yuden DVD-R are the most recommended in these forums.
How old are your set top DVD players? The +R discs won't play in players older than 2005.
How fast did you burn the disc. Burn at the slowest speed possible. You should be able to make a disk image of the disc you've already burned and then return it at the slowest speed available with Disk Utility. Be sure to play the disk image with DVD Player to verify the disk image you created is good.
