I installed Ubuntu 12.10 recently (fresh install, no upgrade). Since then, when booting, the system drop into a busybox shell, giving an 'initramfs' prompt.

when I type 'exit + <return>' the boot continues as normal and everything seems fine. So I suspect a timing issue (as I read in some old threads).

Before meddling with superblocks or grub and the like, I'd appreciate some recent feedback on this (since there is a workaround, I can wait a while, it's just annoying, nothing more).