Plays cd-rw but not cd-r?

[Burnman]

I have a SONY DVP NS700V player. I burnt a movie onto the cd-rw and it played fine I then tried to burn it onto the cd-r and it would not play, tried a number of times and suceeded in making a few expensive beer mats! Strange because I have burnt movies onto these Ritek CD-R before and they have played fine. I am using Nero 6 for burning and DVD Lab for authoring. any ideas?

[dengar]

My DVD player plays CDRW's much better than CDR's, thats how some of them are.