I don't recall anyone mentioning it in the Velocity threads before now. Maybe you could try re-flashing? Something might have gone awry the first time. Sometimes my phone never receives a call at all. I only find out later when the missed call reminder appears. I attribute that to poor timing, with the Ally connected to the internet checking for mail or something at the same instant the call tries to come in. But it doesn't vibrate either, so maybe not related to your issue.
- Zoandroid -
liberum enim electronic fabrica