the latest version of TGTSoft's StyleXP adds compatibity to Windows XP SP1, and also supports changing the Logon Screen.
When i changed the logon screen under a limited account in Windows XP and switched user to see it, the screen went blank, and a curser was blinking the top left corner and the welcome screen didn't appear. I had to press the Reset button
never happened such a thing under an admin account.