I was using a nightly version of Cyanogenmod 11 for a while, and after one of the nightly updates, my vibration intensity has basically gone to nothing. I can still feel it very slightly but it's almost imperceptible. To try and fix it, I've gone as far as restoring to stock everything (including stock recovery etc.) to see if that would fix it, but still the same issue. Is there any chance this is still a software problem, or is it probably an issue with the vibration motors themselves?