How come some icons won change?
There are a number of reasons why some icons won’t change. One reason is that if the file who’s icon you are trying to change belongs to another user, you may not have write priviledges and therefore cannot modify it. Check by looking at the ‘permissions’ section of the Get Info window for that icon. Another reason that you may be having trouble changing icons is that there are several icon-related bugs in various versions of the Finder. Most if not all of these bugs seem to have been squashed as of Mac OS X 10.3 (Panther). In previous version, you may not be able to change the hard disk icon, or any icon more than once per reboot. Additionally, some icon changes may take effect, but only much later.
