With marginal disks, it's more how the DVD reader handles it...
however there are a couple of things that could be done to improve marginal situations in DVD2Xbox...
1 ) When an error occurs read all the blocks up to the point of the error but note the error.
2 ) After this suggest that the user eject the disk, clean it, and re-insert it.
Sometimes misreads can be subsequently picked up on other attempts if the software alows the reader to resume from the errant block.
I do this all the time on the PC to fix marginal disks W/O resorting to accepting data loss.
In other words often the disk is clamped slightly differently, the media cleaned slightly, the laser reflects, differently on a scratch, etc. and a forced retry AFTER an eject and re-insertion, and this can permit a file to be read that failed before.
E.G. it goes like this...
A file error is discovered. It is logged.
The user is prompted to retry now or later.
If now, the user is prompted that they can remove and re-insert the disk.
When re-inserted the directory is re-read to verify that the disk was registered, as it may have not re-registered upon re-insertion.
Then the program goes back to the SAME bad block it had the error before with a different button press which says, A to try again, B to try 10 times, Y to skip this file and continue.
If it succeeds the success is logged.
If it fails the missing file is logged and reported.
Basically I do this with DVD rescue, not that DVD rescue does anything other the ordinary except force retries.... however I can't do this with GDF disks.
It would be VERY nice if DVD2Xbox could...