Hello hakeem,
I can tell you that there are actually four places in the resource files where the word "Admin" appears alone. Those are the following:
Folder under root installation, File Name, Resource Name
~\admin\ModuleDefinitions\App_LocalResources, EditModuleControl.ascx.yy-XX.resx, Admin.Text
~\admin\Skins\App_LocalResources, EditSkins.ascx.yy-XX.resx, Admin.Text
~\App_GlobalResources, GlobalResources.yy-XX.resx, Admin.String
~\App_GlobalResources, SharedResources.yy-XX.resx, LOG.LangPack.Admin
Where yy-XX is the Locale you are editing, such as en-GB, es-MX, etc.
I have found no other "Admin"s ;-)
HTH. If you still cannot get the string localized, please let us know.
Saludos,
Alejandro.