I have a v1.0 xbox with the thompson drive, I am getting disc is dirty or scratched part way through. I am useing dvd decrypter and rietec g04 discs, and the discs worked fine before just started acting up. I cleaned the laser and that did not help

Im thinking it may be the laser and am looking at getting a samsung drive

any suggestions?

I ran into the same problem after using BMI (princo rebadged) media. Sometimes the media would work, most times not.
I tried my buddies ripped games and they worked fine (sorry, i don't know which brand).