OK guys!
I'm back with 2 more BUGs in Vista.

FIRST BUG:
==========
Its related to moving a folder "A" into another folder "B", if "B" contains
another folder with same name "A".
Steps:
======
1. Create a folder with any name in any location. Suppose we created a
folder with name "vishal" in D:\ drive.
2. Create a file in this folder.
Suppose we created a text file "v.txt" under "vishal" folder.
3. Now create
another folder in any location. Suppose we created another folder "gupta" in D:\
drive.
4. Now create a folder (with same name of the first folder we created
in Step1) in this new folder "gupta". i.e., create a folder with the name
"vishal" in "gupta" folder.
5. Now create a new text file with same name
"v.txt" in this newly created "vishal" folder.
To clear all steps, following is a hierarchy of both folders:
D:\vishal\v.txt
D:\gupta\vishal\v.txt
Now lets start the BUG:

Try to move the folder "D:\vishal" into "D:\gupta". It'll ask you whether
you want to merge the folder or not? Click on "Yes" button.
Now it'll find
that both folders contain similar files, so it'll give u following
options:
A. Move and Replace the files.
B. Don't move files.
C. Move
but keep both files.
Now either select A or select C.
Now come back to D:\ drive and u'll see that it still contains the "vishal"
folder although we have moved it to "gupta" folder.
For me it seems a BUG, what u guys say?
[EDIT]
I found that it also happens when you are moving a folder containing system files (like thumbs.db, etc.). It'll ask whether you want to move system file or not and when you'll select yes, it'll move the file but will keep an instance of the folder at source.
[/EDIT]
SECOND BUG:
=============
If we try to delete a file/folder, windows asks our permission "Are
you sure you want to move the file to recycle bin?"
If we try to
<SHIFT>+Delete the file, it still asks "Are you
sure you want to permanently delete this file?"
Now right-click on Recycle Bin icon on desktop and select
"Properties". Now de-select the option "Display delete
confirmation dialog" and apply it.
Now try again to simple delete (moving to recycle Bin) &
<SHIFT>+Delete a file/folder. You'll not get any prompt while moving to
recycle bin but u'll get a prompt again when you'll try to <SHIFT>+Delete
the file/folder. Thats OK. Its used to happen in earlier versions of windows. So
whats the BUG?
Now the BUG starts:

Attach any Removable drive (Pen drive, USB HDD, etc.) and try to delete
(moving to recycle bin) and <SHIFT>+Delete a file/folder.
You'll be
surprised because it'll not prompt you in any situation.
So if windows prompts you while <SHIFT>+Delete a file/folder
in non-removable drives, then why it doesnt prompt you the same in removable
drives?
Either it should prompt in both or it should not.