[X4U] strange authentication

[Xavier Noria]

I don't know why, since I think yesterday a dialog saying that 
"Applications cannot be modified" shows up if I try to drop an 
application into Applications (the user is the admin, this never 
happened before). I took a snapshot:

     http://www.hashref.com/img/authenticate.png

Another dialog requiring the password shows up if the admin user tries 
to delete an application from Applications.

In addition, I don't know whether this could be related, but Gimp.app 
does not launch. That startup rectangle whith the logo and a progress 
bar appears as a grey rectangle and the launching seems stalled.

Do you know what can be happening?

-- fxn