sometimes,it's becos of the game DVDs becos pirates uses cheap quality ones(i think its read speed is 1x only)..but if most of ur cd cant play,im thinking of:

a)ur lense is dying
b)ur lense need re alignment
c)ur modchip is dying or is not soldered properly

ps:ive been experiencing the same problem like u last year too..n the magic word is: djinn...

haiz djinn,im thinking of doing part time promoter 4 u lar