PS2 not playing dvd games

I bought a PS2 recently (It is a pal model), there is no chip in it, it hasnt been opened yet.

My problem is this - verytime I put a DVD ROM game in there it wont start the game and says the discs contains not data, but the DVD Videos work fine.

Does anyone have any thoughts?

Silly question, are you sure it's a PS2 game? If so, is the disk dirty? If not, take the PS2 back to the trader, prove your point and swap the PS2 out.

Thanks for the quick info. Yes they are PS2 games, I have played them on my friends PS2 so I know its not the game. I have tried about 4 different games.

Someone told me there might be a setting somewhere this can be enabled and disabled ??