The Associations area under Classes Cleaner is where all my trouble existed.
RegVac found 14 entries under that scan. Seven of them finally ended up in the cantremove text file.
Of the seven remaining, it removes only one.
The other six are:
HKEY_CLASSES_ROOT\Local Settings\Software\Microsoft\Windows\Shell\Bags\18\shell HKEY_CLASSES_ROOT\Local Settings\Software\Microsoft\Windows\Shell\Bags\24\shell HKEY_CLASSES_ROOT\Local Settings\Software\Microsoft\Windows\Shell\Bags\25\shell HKEY_CLASSES_ROOT\mapi\shell
The one key it will remove is
It is recreated every time it is removed, so not much point in removing it.
I added the other six entries to the can't remove list and ran the program with no problems. [284 items removed]
Problem seems to be solved for my computer. Whether it will work on all Vista computers is an open question. Looks like Vista doesn't want its associations messed with.