The tree on the DVD-RW is this:

Top Folder
Sub-Folder-1 (Good) > Sub-Folders/Files good
Sub-Folder-2 (Good) > Sub-Folders/Files good
Sub-Folder-3 (Good) > Sub-Folders/Files good
Sub-Folder-4 (Good) > Sub-Folders/Files good
Sub-Folder-5 (Good) > Sub-Folders/Files good
Sub-Folder-6 (Good) > Sub-Folders/Files good
Sub-Folder-7 (Bad) > Sub-Folders/Files bad

When I said that I had created a new folder, that turned out to be not exactly true. The folder and its contents were ready to burn to the dvd. (only realised that this morning). but the point remains the same, I can manipulate the files/folders in Folders 1 - 6.

Folders 1 - 6:
I have copied Folders 1 - 6 to the hdd with no problem.
I can read the files on folders 1 - 6 both on the dvd-rw and the hdd with no problem.
I can print files from Folders 1 - 6, on the dvd, with no problem with no problem.

Folder-7:
I can open the folder and sub folders on the dvd.
I can copy the folder structure onto hdd, which suggests it is recognized.
I can see the attributes of any file under Folder-7 or its sub folders. (file size etc.)

I cannot open any file under Folder-7 or its sub folders.
I cannot copy any file under Folder-7 or its sub folders.

What is the extention of the file that you are trying to copy?

the extensions are the same on all folders. .doc, .xls, .pdf, .txt

When trying to open .xls, .doc & .txt files on folder-7, I get:
files.jpg
When I click on pdf's, they just open up adobe 8 application but not the file.
gifs & jpg's do not open either. I need to install PaintShop Pro 7, which is how they were created.

When trying to copy files on folder-7, I get:
Word-error-2.jpg

For the .doc & .xls, I am still using Office 2003, which is how they were created. I don't think that I was using Office XP at that time, but I don't think that is the issue because of the .pdf & .txt.

I cannot set the security because the folder is still on the dvd. I could only do that if it was on the hdd. having said that, when I copied the folder structure (remember the files do not copy) I was able to reset the security on the folder structure on the HDD. It's a mute point because the files are not there.

Does my explanation make sense?

Nice write up lucianp. If nothing else, I hope you've learned that when you make a CD/DVD you should always verify that the file has been copied properly.

Open the written file or play the recording from the CD/DVD via the Windows Explorer. This will prove to you that the copy is good.

Gandalf,
I absolutely agree, and I did open some but not all 404 folders with 32,927 files. That's a bit time consuming.

I used to have a little shareware that compared file sizes. With one or two files opening ok and the files sizes comparing ok, one tends to assume....

Assumes? This is what happens, when one assumes.
Which is taking more time now?

Gandalf, you're right of course. One should never assume but I am sure that I am not the only one. there are probably not too many people who do check ALL of the files, particularly if doing scheduled backups. At least I checked some and compared file sizes on all the others. When copying one or two files, I will agree that one should verify, but when copying almost 33,000 files, I don't think so.
I think we need to spend the time now trying to find solutions, hence the reason for coming to an informative forum.

Any help is appreciated

thanks.

This problem is quite common. A couple of possible fixes that have worked for other people:

Disable your antivirus completely, then try to copy the files.

Use ISO creator tool like IMGBurn to make an ISO from the DVD - mount the image and copy the files from the mounted image.

Try downloading a zip program like 7z - see link below. Right click problem folder > select 7z > select add to archive. If the folder zips successfully to your hard drive to to extract or open the files from there.

7-Zip

By default anti-virus programs are always on. How do you actually turn off virus checkers once they're installed?
Will I need to uninstall to do these tests?
I have AVG Anti-virus and Windows Defender installed. Do I need to disable/uninstall both?
I am running Vista Home Premium SP1.

thanks