Movie DVD Backups won't play

[Hernandez, Roberto]

Regards,
Hope you can help me to find out what's happening with my backup discs.
I used to backup my movie DVDs to keep original discs at 100%
But since some time ago, backup discs can't be normally played, I hear
audio but can´t see video.
PowerDVD, NeroVision, WM, all video players show a black screen.
If I move the application window, video 'appears' and then 'disappears'.
Never the less, backup discs can be played in home DVD player normally.

I don't think can be a codec problem, 'cause original discs play well in PC.

Any idea?

Thanks in advance.

P.D. My PC is wXP PRO sp2, 1024 Mb Ram.