don't have right permission, can't add or delete folders :(

HI

I have a problem.

My mac is a macbook pro came with OSX 10.6.3, all was fine.

Upgraded to version 10.6.8 and now i can't add or delete any folders on the desktop.

It says i don't have the right permissions.

But i am using the admin profile so it should be working!

Also when i want to delete a folder it asks for admin password, and when i write it in it's as if nothing worked....

Rosaluce