Some PC drives are much fussier than others. I have 2 DEll PCs - a slimline 5150c with a laptop style combi drive, and a full size E520 with 2 "proper" optical drives. When I've tried watching rented DVds on the former PC, linked to my TV, I've several times experienced read error phenonema ( stuttering , freezing or video corruption) , but when I then test the same DVD in my other PC it reads OK.
With my own DVDs ( which are better looked after) both PCs read them perfectly. So read errors can be due to the DVD, not the PC, even if the DVD plays OK in a different setup.
I would guess that standalone DVD players behave similarly i.e. that some are more tolerant or better at error correction than others.
I've also observed that some PC dvd software is more tolerant than others, I've rented films that froze when watched with PowerDvd but worked ok when watched with Windows Media Player