Ok two basic problems could be the media your using, and the burn speed. Good media eg TDK, Ritek, or anything else thats recommended on this forum is the go. Second burn as slow as you can bear. Another less common problem is macrovision protection. Check the manual that came with the DVD player for a macrovision symbol on the inside cover. This protection can sometimes detect a DVD-R and reject it. It usually only happens when the movie you copy is macrovision protected as well.(unlikely)
thanks for ya help,the media im using is good TDK DVD-R and im burning at 2x/,i cant check tha manual for the symbol as it didnt come with 1 when i brought it