It now seems I mis-read your first post. You said the folders and files looked OK but the files are inaccessible. I thought you meant the disc itself was "access-denied."
In that case, probably you should check the write quality on each DVD+RW disc after each burning. MKMA02 is good in GSA-4163B. The fact that you used the same disc in another drive before does not really mean much. The disc probably has defects or the Lite-On drive dislikes MKMA02 or something else. Unfortunately, lots of drives seem to fail with the latest 8x DVD+RW disks. They can't recognize them at all so no PIE/PIF scans. Can your Lite-On DVD-ROM drive test PIE/PIF scan on the first MKMA02? Sometimes full format or something helps.
From my own experiences, LG DVD writers of the latest seemed to read disks better than Lite-On drives. But Lite-On drives are much faster readers.
BTW, with software, I meant all the installed and running software things related to CD/DVD. InCD and drivers included. At any rate, rewritable media give too many problems compared to HDDs.