PS2 don't read dvd-r

Houston,
I've a problem!
My ps2 don't read Princo dvd-r anymore.
Before yesterday I played with it using without problem those dvd-r.
Now it can read only cdr, dvd+r, dvd-r (from Maxell) or dvdrom (original game, not backup).
With Princo and Verbatim dvd-r, it starts, display "PLASYSTATION2" logo, than freeze.
Any ideas?

Lopaolo

possible laser is on its way out or just needs a clean ???????????

put you ps2 verticle!! sounds stupid but it works!!

can some1 please tell me if there is a disc that alows you to play import games on a ps2 so i dont have to use a mod chip? they have one for GameCube and was curiouse about a ps2 1!