U11 problem in DVD-S52

Recently bought DVD-S52. It is not able to read a number of commercial DVDs of type DVD-ROM (which are working fine on my comp). After attempting a number of times, it displays “Check the disc” on the monitor and shows a code U11 on the player. This happens some times even when I skip the chapters continuously or even select a second or third movie that is stored. I am getting similar experience in some of the VCDs also. Any similar experiences?

I have 2 DVD S52 and never saw a U11 error code