Although its unlikely that you have two bad discs, don't let the fact that they both play ok fool you. Only way to tell if they really "play ok" in a player is to watch the entire movie and every feature available on the disc, in essence, watching the entire disc. When DVDFAB does the initial scan and finds an error, the error may be in the movie section or perhaps some feature (i.e. bonus,) section and will report the error regardless. If your backup is movie only and it reports a read error again during the copy task, then yes, the movie section is likely where the error is. Depending on how bad the error is, in many players you might simply see a quick glitch, such as a few seconds (or less) of pixilation, but the player can usually recover and continue with the movie, whereas Fab will stop and report the error. If you blink, you might even miss it during playback. I have had several movies that had small errors, over the past few months. On some of my issues, I could hold the disc in a well lit room and at the correct angle, I could see what appeared to be a tiny bubble (the size of a pin-point) in the disc. Sometime you really have to look carefully Of course I exchanged the discs and had no problems after that. These were obviously manufacturing (pressing) errors and they do occur.
Incidentally, you should attach the dvdfab_internal.log file and the fabcheck.log (if one was generated) files. The latter is only generated if the task crashes, and not necessarily for a read error, but if its there, include that as well. If these are recent purchases, you should be able to exchange them, and should, if they are in fact bad.
