M G Intern: They could have been bad copies but more likely they were "Region 1" for US and Canada. She was most likely playing it on a Belgium DVD which is "PAL". We can't buy them in US but Euro DVD players play ALL the formats - The parent most likely can go to the menu and click on Region 1 and it might play.
Ask the parent if they have a "PAL" format player. If they do there are some great PAL format movies on E-Bay. mory