Despite your rather long thread starter, I'm including it all, as I expect I'll be touching on various parts of it as I go.
Media - Sony - no problem there.
Write Speed - 4X - Good there, too.
Verification after Burn:
I usually don't make too many comments to people who do this, as it seems to keep them happy, and it doesn't harm anything.
However, you seem to place a lot of stock in this feature, and I keep asking myself, "Why"?
When a disc is being burned, whatever engine you use, each sector, as it is written, is verified before the next sector is started. If your burning engine hasn't kicked out with a write error before the end of the burn, then the subsequent verify isn't going to tell you anything you don't already know. In other words, Clean Burn=Clean Verify.
On the other hand, if you've burned a disk too fast (not a problem in your case), anything from pixelation to a complete freeze can occur, and that won't be caught by the verification process.
As many here do, I use my eyes to watch the disk after a burn, and if there are any problems, I tune down some of the settings, and re-burn. (Yes, verification won't fix any problems, either).
Since the VSO engine seems to be failing on the verification pass (Task 3 - Failed Error=100), I'm not surprised that the drive door isn't staying closed, either. The problem with VSO is a suspected bug, but as the program isn't written by or updated by the DVDFab authors, all we can do is bug VSO software, and hope they fix it.
Your other problem: may be a corrupt write to your HD, which is why Fab is not updating when you try to access it.
Check it with Windows Explorer and see if that program will list the file. That, however, won't prove much. According to your notes, Nero file reallocation failed when you tried it, which causes me to think it's a HD error. (as well as Fab not reading it at all).
There may be a bad sector on your HD that's not mapped into the HD table, and the only way to fix that is to re-format and start again (unless someone here knows a utility that will update the HD Table).
I also noticed you've got an ATI card in your system. Were all the utilities on the ATI supplied disk loaded on your computer? If so, you may want to consider getting rid of all of it except the drivers, as I had problems with some software as long as those utilities were on my system.
Not much in the way of solutions here, except forget the verification, and see if you can find anything that'll confirm a corrupt file for you.