I have had a nightmare with DVD+RW and the LDW-811. I don’t know if it is the drive or is it the media, but it is very extrange (have only tried RICOH media from Sony and That’s Write). Here is this thread for some info about the situation:
I need to know of reliable DVD+RW media for burning with the Liteon recorders. I need very good results for DATA backup. I apeal to your experience guys, as you can see the Kprobe scans of that RICOH disk were near perfect but after only some months the disk was unreadable.