On Fri, Apr 3, 2015 at 5:49 AM, Patrick O'Callaghan <pocallaghan@gmail.com> wrote:

kernel-3.19.3-200.fc21.x86_64
kmod-nvidia-3.19.3-200.fc21.x86_64-346.47-2.fc21.4.x86_64

The failure happens immediately after selecting the kernel from the boot
menu. A stack trace appears which I'll post if someone tells me how to
capture it.

Working fine with my GTS450 but my kernel module was built locally by akmods, not downloaded from the repos... 

Richard