Gmail notifications will not vibrate

the setting is turned on, i have attempted multiple times, i get the icon in the notification bar, i get sound (on accounts set for sound), but no vibration

never had this issue with a previous phone and it's a big deal to have vibration working... i keep 3 gmail accounts going on my phone the most active of them set to vibrate with no sound (it's a busy enough account that having sound turned on would be a very annoying problem)

phone is a kyocera hydro air