whenever i get read errors using XBC or Schtrom, it's usually because the disc it is reading from is scratched. try cleaning the disc and running it again. it should work.
i am also assuming you are using the latest version of Schtrom?
not sure of the best way...i usually just take a very soft cloth, will use some "CD cleaner" (which smells just like diluted rubbing alcohol), and clean from the center straight out down the radius of the DVD. has worked for me in the past. maybe someone else can tell you the best way to clean.
