This problem has been sometime for me. Bumblebee-nvidia is used for graphical applications. No matter what kernel version I use, the first boot after a complete shutdown the computer would freeze on plymouth screen, I’d have to manually hit ctrl+alt+del to reboot and then it could load into X.
Since kernel 3.10, everytime I did a kernel upgrade, my fedora just wouldn’t boot into this new kernel. Also I have previously set my TIMEOUT to 0, which means I won’t have a choice during boot. The problem is not big nor severe, but it did took me some time to figure how.