I can confirm that the pxelinux.cfg files for hosts generated using cobbler version 2.1.0+git20110602-0ubuntu26 generate gpxe/menu.gpxe configurations no matter what the setting in use_gpxe.
Unfortunately fixing "filename '/pxelinux.0'" has no effect when booting hosts. They're still trying to boot gpxe/menu.gpxe
I can confirm that the pxelinux.cfg files for hosts generated using cobbler version 2.1.0+git201106 02-0ubuntu26 generate gpxe/menu.gpxe configurations no matter what the setting in use_gpxe.
Unfortunately fixing "filename '/pxelinux.0'" has no effect when booting hosts. They're still trying to boot gpxe/menu.gpxe