My LiteOn drive can't read DVD-R



I have a DVDRW drive (LiteOn Slimtype SOSW-833S).
It can read the media of type (DVD-ROM, DVD+R), but when I put one media of type (DVD-R), it takes about 3 minutes to recognize and open it
and in some cases takes more than that, in other cases it can’t play it altogether.
What’s the problem with it?