No luck on file system error 2147351799

I’ve seen a lot of posts on this type of error-message, but only people who are copying dvd-movies.
I’m trying to read .wav-files from a DVD-RW on my laptop which has a LiteOn Slimtype Combo LSC 24082K. I’ve updated the firmware successfully. I have used LtnRPC to make it region-free. I have installed DVD43 but still i can’t copy the files to my HDD. Small files .lso and .ovm (less than 500k or so) copy ok, but no wav files. I even tried making a zip-file of it all, but with no luck. The .wav-files are 24-bit, 48kHz and 96kHz, recorded at my studio, so it’s not even copyrighted material.
Any ideas?

What has region stuff to do with WAVE files on a DVD???

try removing upper/lower filters