OK, I was a little slow on this one;
If you play the DVD (I used VLC) to open the disk to the starting menu then the disk becomes accessible & reads as it should.
Which then brings up the next problem that is as soon as the disk is read DVDshrink closes, reopening DVDshrink just allows me to repeat the process...
If I try to backup a DVD structure that is saved onto the hard disk drive it behaves the same as if it were reading the DVD disk.
So I can not backup a DVD using DVDshrink in Leopard on this iMac.
On Sabayon Linux 3.4e & f, a similar problem happens with Wine (different computer), except after the first closure when you reopen DVDshrink it allows you to continue & do the Backup.
Any idea's anyone?