I have a NEC 3550 dvd-rom for about 2 years. I didn't have any problems with it until yesterday. I got GRID and and when i put the dvd into my dvd drive nothing happens, it just shows a blank dvd , fails to read that dvd. I tried also more dvds and half of them NEC failed to read. The Cds are working fine. It seems that my NEC can't read dvd-r or there is something else ? Maybe the laser is just dirty ? Anyone knows what the problem is ?