Some burned dvd-r movies skip in my standalone dvd player but not in my computer dvd player. PLEASE HELP?

Ok... This problem is really boggling me. I download movies and then convert them to dvd and save them as a dvd image file using roxio 2010. Then I burn them using the slowest setting (4x) I have used 4 different brands of dvd-r: HP, Sony, Memorex, and Verbatim all 16x dvd-r. All of the media skips in the same spot so I know its not the media. Some movies skip, some only a short time, some a longer time and it's usually only in the beginning right before the movie starts only during the opening credits that they skip. When the movie starts it usually plays great all the way through so right when the picture from the movie appears the skipping stops. I also see it skipping at the end of movies or during the parts of the movie when words appear. If the movie skips it's always just that specific movie. I know this because I have downloaded about 5 different versions of the same movie and it skips in the same exact spot. Some specific movies play perfect. My computer is only about a year old 4gb ram quad core pentium. I have tried to play these movies on 5 different dvd players, and 4 different brands of dvd-r media so that's definitely not the problem. My hardware or software (roxio 2010) isn't the problem... I have tried playing the movie on my computer before it is converted and it plays fine and also i have tried playing the burned dvd in my computers dvd player and it plays fine. Can it be a copyright thing that producers implant into certain movies to cause them to skip? I do find that movies by Warner Brothers don't skip and ones by paramount do most of the time. I have heard maybe its because standalone dvd players are more sensitive than computer dvd players so maybe thats why it skips? But if thats the case then shouldn't all the movies skip? I am at a loss for words. PLEASE HELP!!!!!!!