dvdrip: .ifo files not copied

I'm running into the following problem with dvd::rip 0.98.8:

Subtitles generation works only when ripping a mounted DVD or a loop 
mounted DVD image.

If the image is lying unpacked in the filesystem, I'm getting
"WARNING: no IFO files found - vobsub feature disabled." and tmp/ifo/ is 
empty.

The problem seems to be the $dvd_mount_dir usage in copy_ifo_files().

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed