I did tried to burn some of my data into a DVD-R and I burned it in my school's DVD burner. However, my computer's DVD-ROM could not read the data DVD-R but the one in school is OK. So, I wonder why will this happened. Also, I don't understand that is there any difference between the DVD-R and the DVD+R. Are they the same? Which one should I use so my computer can read (my computer is a PowerMac G4 with DVD-ROM). Thank You.