all my rip Programs stop at 48%

[dar1125]

I'm actually quite a lucky Guy, I have an svideo jack on the Gforce and so I bought a Svideo2AV imput to connect it all to my VCR , in other words once the movie has been put onto my hard drive, I can record it straight onto Video.. as well as do the burn thing and get it on to disk.
some movies are fine, they load up on to the HDD in about 40 mins with no problems, But others.. it stops, then tells me about an unreadable area on the disk, I've used a few rippers which have the same problem on the same DVD's but the DVD's can play very well on DVD player (computers as well as My own) Does anyone know about this or is this normal?
many Thanks

[Innershield]

Is the disc scratched at all?

[dar1125]

no more than the rest, but the strange thing is that all the DVD's that do this all stop at 48% surely if there was a scratched problem the creash problem would vary accross the board,??