The selinux base policy 20070329 has something wrong with ssh, as described in http://oss.tresys.com/projects/refpolicy/changeset/2373 . The consequence is that user can't log in using ssh when using targeted policy. Reproducible: Always I provide a new ebuild based selinux-base-policy-20070329, which can be downloaded on the following URL: http://lcs.ios.ac.cn/~scwang/selinux-base-policy-20070329-r1.tar.gz
new policies which include the fix are in portage.