Does ps2 have a will of its own...?

[Rakhshasa]

Hallo there...

I have a problem in playing some backup games...
Actually it's just a few days I have this problem:my ps2 stopped playing games written on TDK's DVD+R in the night after I was been playing with those games all day long... And the dvds haven't even a scratch!
Now there is no way I can make them work again...
So maybe my ps2 decided that I shouldn't waste time in playing videogames and I should find a job...?
Or do you think that it's just my dvd reader lens that isn't clean? If so,how do I clean it?
Or maybe my modchip has messed up everything... But I think this is strange,because I can play with other games...

Well,I have also another thing to ask:how do I backup original games?
I used dvd decrypter,then Alcohol to backup Soulcalibur 2 pal,but it doesn't work... Is this procedure correct?
I want to backup Z.O.E. 2 too,but before I waste some more dvds I would like to have an answer on how to backup!

Thank you for help!