DVD writing problem

I have recently purchased a Lite-on LVW 5026, and am experiencing difficulty while copying a video file from the HDD to a DVD.
I have been using the regular DVD+R and DVD-R discs made by Sony and Moser Baer. My problem is that halfway through the process of copying, it stops and says “An wring error has just occured. Please check the target disc.” I am unable to find out why this is happening. This phenomenon seems to be random, but there have been a few successful recordings as well (on discs from the SAME box, too).
I do not know where the problem lies.
Kindly help.