It's not a driver solution, it's to do with the region coding on your DVD drive. Apparently Macs are more tricky to sort out that PCs. Info here:
http://lowendmac.com/fishkin/06/0623.html and (depending on your OS) here:
http://www.ilovedvd.co.nz/dvddownloads.asp . Though if you're lucky, it seems as if the free VLC player may do the job. Be careful - once your DVD drive is region locked (you are normally allowed to change region 3 or 4 times) they are difficult/impossible to unlock.