Computer won't recognise new dvds but will recognise old ones!?

All my older dvds work perfectly in my laptop but most new dvds that I buy don't work. I have a Lenovo N500, windows vista. When put the dvd in I can hear it starting to spin but then stopping and doing this over and over again. When I go to my computer, it says there is no disc in the drive. When i go to device manager it says the drive is working perfectly. Do I need to install an upgrade of vista or something or is there some program that will enable my comp to read these dvds?
All help much appreciated!