I am having a similar problem, albeit a bit different.
I have the SCPH-3001 model PS2. Ever since I got ESPN 2K5 back in August/September 2004, I have had minor disc reading problems. Every now and then, I'd pop in a game and get the DRE. A simple eject/re-enter procedure seemed to fix this. This lasted from then until yesterday.
I tried to play ESPN 2K5 and I could get it to read, but after the "Playstation 2" logo came up the screen just stayed black forever. A couple presses of the reset button resulted in the same thing. Then I tried to play GT4. This time, I got the white words to appear (the words that come up right after "Playstation 2") but another infinite black screen. Then I tried NFS: Underground 2 and my driving force pro wheel activated, but I never got any words to appear and never got past the black screen.
The weird thing is that my PS2 is reading my games, its just not playing them. Strangely enough, GTA:SA is working fine without any problem, as well as all of my older PS2 games and PS1 games. None of my CDs have a scratch on them. I have a lens cleaning CD and have performed the lens cleaning cycle several times to no avail.
I read the FAQ and I don't know what to do. I have tried standing my PS2 on its side but that didn't work either. I read the part about how PS2s might only read CD-ROM games and not DVD-ROM games, but all of my games are DVD-ROM and some are working and some aren't (None of my games that were released in late 2004-present are working, except San Andreas). I got my PS2 in July 2001 so the warranty has been up. On top of all this, my network adapter mysteriously no longer works. This is really pissing me off because I spent all this money and now I can't even play my newer games and GT4. Can anyone tell me how I can get into contact with Sony?