how to remove remote printers

using the gnome shell, when you click on system/administration/printing... there are a list of printers under the heading 'remote printers', and we would like to remove them.... we've tried going into the /var/cache/cups/remote.cache file. but even though the file is empty the remote printers still show..

when selecting any one of the remote printers using gnome, the delete button is not highlighted..

how do we get rid of these remote printers ???