Default Vibration disappears from time to time

Hi,
I just got my new black 32GB Nexus 5. Looks like I do not have all those defects every body talking about. But I seems to have one new that I couldn't find anywhere so far.
Some times my vibration haptic feedback stops working and then comes back. It can be on the 3 buttons in the bottom or while typing on the keyboard.
Anyone has it also. How do I fix that?
I'm on stock ROM, only rooted.

Thanks in advance.

Sent from my Nexus 5 using XDA Premium 4 mobile app
dmatik