Not all DVI is create the same. There's 3 variations: DVI-A, DVI-D and DVI-I corresponding to Analog, Digital and Integrated digital & analog. There's separate cables for the DVI-D and DVI-A&I. To make things even more confusing there's two variation of DVI cable based on bandwidth. Single link has less bandwidth than dual lingk, though single link can handle more data than 1920x1080 at 60Hz. Further information can be found
here.
Hundreds of mail order web stores can supply whatever DVI cable you need (and almost all of them will be cheaper than your neighborhood box store).