Default [Q] multirom Nexus 5 4.4.4 CM 11 Kernel

hi All, i have a Nexus 5 running 4.4.4 rooted and multirom v26.
I have tried changing the kernel to the CM 11 (4.4.3 - 4.4.4) and only get a black screen on boot! If i am connected to usb my PC gets the extra drive.
I have tried about three times! i have tried rooting with the Nexus Root Toolkit v1.8.4 and manually rooting both with the same results.

Any ideas?
If this a known problem, am i doing something wrong?
Should i use a different kernel, if so which one?

Dave