I reinstalled 10.4 today on a 1.5 year old MBP. All updates have been installed. There are no other accounts on this computer but mine. But now it needs me to autheticate (needs my password) any/everytime I try to move a just-downloaded program to the applications folder or when I try to move an application to the trash program, and I've never had to do that before (it doesn't matter what type of application, they all need authetication. Here's the message it gives me: In order to use Finder you need to use your password - it then has a the password/name box below.(when trying to delete) The program (name) is not able to be moved because "Applications" can't be modified. Below that it says "authenticate" - then it gives the name/password box and "ok" - it does nothing. (when trying to move a program to applications) (not exact translations - translated from spanish) Please help!