This isn't a bug, it's intended behaviour. initramfs-tools bails out to prevent generating a *broken* initramfs for your old kernel. If and when the dapper kernel is installed, it will get an initramfs generated for it that uses the new udev, and all will be happy.
** Changed in: initramfs-tools (Ubuntu) Status: Unconfirmed => Rejected -- upgrade script problem https://launchpad.net/bugs/56260 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs