Can a PS3 play BD games perfectly but NOT BD movies?

[cesca]

I've had a PS3 drama for a few months - I left to study abroad for a semester, just before I left my PS3 got the YLD...so, after a stupid process of returns and re-returns from Sam's Club (don't ever buy there, they have bad warranty!) I got (we'll my family actually) got a "new" 60 GB PS3 (Mine was 60GB) and they saw a Bluray perfectly, and my brother's been playing for a few days without a problem - YET now they tell my BDS don't work, he tried a few, that do work a normal BD player my dad has on his room, so I know it's not the BDS.......can this actually be possible? It read BD games perfectly, but not movies - I don't want them to send the thing again because they're probably pretty fed up with the whole process.

Any tips for what they can do?