see all glibc installations
for example, on a problem machine I found:
glibc-2.12-1.80.el6_3.5.i686
glibc-2.12-1.80.el6_3.5.x86_64
glibc-common-2.12-1.132.el6_5.2.x86_64
glibc-devel-2.12-1.132.el6_5.2.x86_64
glibc-common-2.12-1.80.el6_3.5.x86_64
glibc-2.12-1.132.el6_5.2.x86_64
yum erase glibc\*
install headers
yum install glibc-headers.x86_64 0:2.12-1.132.el6_5.2
fixed
yum install glibc-headers.x86_64 0:2.12-1.132.el6_5.2
fixed