Im having a simlar problem ... Today is my first day back to work since getting the phone, so I go to Settings<Sound & Display<Sound Profile and slelect "vibrate" since at work, i want everything to be vibrate only.
Hours go by and i notice I havent gotten any alerts... look at the phone... and... I have... just silent.
Seems the ONLY thing that will vibrate is phone calls. I tried texting myself from multiple phones, emailing from multiple email accounts/providers, and 2 different twitter progs.
All of them are set to vibrate as well as alert, and, by me setting the profile to "vibrate" all alerts of any kind should vibrate.
What am I missing?