Copy od dvd made in sony video recorder won't work in xbox



I have successfully made copies of videos on my computer but my computer dvd recorder has broken–so I bought Sony VRD_VC20–thought i could transfer old movies and use it as an axternal drive as well. The +R dvds produced from my computer before it broke worked perfectly in the xbox, but when made with this sony device they will not play in the xbox. They will however play in a cheap dvd player. Any suggestions? We use the xbox for most of our movie and home movie watching. Thanks!