Fickle playing of DVDs: some work, some don't!

[Macgraphix]

Hi there,

I'm having a problem playing perfectly legal store-bought DVDs and I can't figure out where I'm going wrong...

I've used about 5 different DVDs to test this with, all work fine in a regular DVD player.

1.Some DVDs play fine in VLC
2.Some DVDs (from this one particular DVD rental store) won't even register on my computer, there's no icon, no apps open, it just makes a whirring noise three times then spits the disc out.
3. Some other DVDs from a variety of other stores and regional codes won't play, even through VLC.

Any ideas about the ones that won't even register? When I've got Mac the Ripper open it just says "no disc inserted" when I tried it.

Thank for any help you can give

 

[Chupa Chupa]

Only thing I can suggest is to take the DVD to a store and see if it loads on a demo machine. I've encountered situations in the past where a particular DVD would not play in my laptop but would play on a set top player, and vice versa. Usually its due to a poorly duplicated DVD or poor quality DVD blank and the ability of the players laser to pick it up & correct for it. But it could be a hardware issue so worth checking out if you can duplicate the issue in a store's machine.