There are two types of things that are displayed on your desktop:
1) things that are on YOUR desktop
2) things that are on ALL USERS desktop
Messing around with stuff on all users' desktop requires permission.
This is normal in Vista; however, I imagine this will be a lot less painful
in future versions of Windows.
--
- JB
Microsoft MVP - Windows Shell/User
Windows Vista Support Faq
http://www.jimmah.com/vista/