There was a version bump for system-config-printer-gnome and older versions were removed but now there is no stable version for x86. 1.3.11 is stable for all keyworded platforms but x86. I couldn't find a good reason for that. In fact the changelog includes that following: 30 Sep 2012; Raúl Porcel <armin76@gentoo.org> system-config-printer-gnome-1.3.11.ebuild: alpha/arm/ia64/sh/sparc/x86 stable wrt #435072 so it appears that this is just a case of a fat finger error.
+ 07 Nov 2012; Pacho Ramos <pacho@gentoo.org> + system-config-printer-gnome-1.3.11.ebuild: + x86 stable keyword was dropped by error, bug #442240 by redneb. +