I use Eudora 7 for email and in previous versions of windows I could open the
C:/program files/qualcom/eudora folder and see all my attachment folder,
mailboxes, ini files, etc in case I needed to transfer them over to another
computer. In WinVista they don't show up automatically.

Instead when i open that directory a new menu item appears on the toolbar
right between Previous Versions and Add to Index… that is called
Compatibility Files. Hovering over it shows a popup that says "Show
Compatibility Files for this Directory" and clicking on it opens what
essentially looks like a new directory with only the files I mentioned above
in it.

But you can't select all, click and drag for selecting a range of files, or
ctrl-click or shift-click to select multiple files to copy.

I'm not sure if any other directories act like this, but I've done multiple
searches here and on the web in general and can find no mention of this
"feature" at all!