Tried to back up Fable, seemed everything was going well. Running evox 2.6. Stuck the backup of fable in the box, normal opening, got to the start menu...opened up my save game. Took a while to load (that's normal, I guess), then told me I had a dirty disc. I thought there might be something wrong with my save, but it works fine with the original.
I had the same problem Eperaza. I first copied Fable with a princo disc wich I had the problem. I was pretty pissed off that my original worked perfect and my copy wich was perfectly clean said disc is dirty. I then copied it to a Fugi DVD-R and it works perfecto. It may just be the type of media your using. Hope this helps!
qwix for the .iso, nero to burn. this method works. i first used craxion to make the .iso, and it gives you the dirty disc error