I would copy a profile from a user’s system, wipe it, reinstall and then copy the profile back only to find that if the person had admin rights, no problem – everything worked. If not, even after I gave their new account full permissions odd things like missing backgrounds would happen (Windows XP theme settings).
With the help of my wife (who made me describe in length the process), I tracked it down to the SID being different in the profile registry settings. The registry hive for the profile had security set to the old SID, whereas the new account had a totally different one.
Once I followed the steps here and changed the permissions to allow the new account full access, everything worked.
Just thought I’d pass that along. Hope it helps someone.