Time Code on DVDs being recorded

I recorded a DVD of my Home Movies that are stored on my computer in mpeg format. I used NERO 6.0 to put the mpeg files on DVD. NERO uses a converter to install the files on the DVD being burned. After completing the DVD, I discovered that with my DVD Player, I cannot go to any certain time slot on the DVD. When I try to do that, my DVD player tells me that this function is not authorized on the this DVD. I can do this on the purchased DVDs that I have. If I want to go to 30 minutes in on the DVD, I can input that, and the program will start playing at that point. With the DVDs that I recorded, I cannot do that.