http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/dev-db/postgresql-server/postgresql-server-9.1.2.ebuild?revision=1.1&view=markup SRC_URI has: http://dev.gentoo.org/~titanofold/postgresql-initscript-1.2.tbz2 from March and not newer: http://dev.gentoo.org/~titanofold/postgresql-initscript-2.0.tbz2 which includes the making /run/postgresql fix.
*postgresql-server-9.1.2-r1 (10 Dec 2011) 10 Dec 2011; Aaron W. Swenson <titanofold@gentoo.org> -postgresql-server-9.1.2.ebuild, +postgresql-server-9.1.2-r1.ebuild: Fixes bug 394171