After upgrading the bios of my MB to 3209 (Asus Sabertooth P67), my kernel 3.2.12 failed to boot. Upgrading my kernel to 3.2.16 solved the problem, i assume appending pcie_aspm=force to my kernel would have resolved it too (seems like it is a known bug resolved since kernel 3.2.14 & 3.3.1) Reproducible: Always
This problem is mentioned here : https://www.kernel.org/pub/linux/kernel/v3.0/ChangeLog-3.2.14 You should think about stabilizing kernel 3.2.16
This is included in the latest version of gentoo-sources-3.2.21