I have 3 desktops setup through mission control and I have set "activity monitor" to start up in the 3rd desktop and also set that specific desktop with a certain back ground color. This does not occur instead activity monitor starts in the second desktop with the color set for the 3rd desktop. More importantly is the 3 desktops is a non administrator account and when I log into the administrator account the background has changed. This suggest some application acquired privilege to change an administrator back ground image.