I'm not sure if you're talking about the deadly "Disc Read Error" but I was able to fix my own without having to bother with sending my PS2 off to Sony. I did that once and it took weeks to come back so I resorted to this. As expected, it voids your warranty but it fixed what ailed me.
http://www.g4tv.com/xplay/features/45797/PlayStation_2_Disc_Read_Error_Fix.html
http://www.g4tv.com/xplay/features/45797/PlayStation_2_Disc_Read_Error_Fix.html