SLV-D360P Won't Play Some Disks It Should Play

I have the Sony SLV-D360P model DVD/VCR, and the thing plays some DVDs but not others. Some disks go in, it says loading, then after a few seconds it'll start playing. Other disks it says loading then doesn't play. I just keep hearing a whirring sound like the player keeps trying to read the disk. The disks that don't play in the DVD player do play in the computer, and I haven't messed with any region settings on the computer, which I've read I might have had to have done if it were an issue with the disk’s region. Also for example, we got the first two disks of a show from Netflix recently, and the player played the first disk fine, but the second one won't play, and I doubt netflix would send two different region disks together to the same person. Cleaning the disks has no effect, and turning the player off and on again didn't help. Has anyone else had this problem/have any ideas?