I'm playing with my iphone here, and I have noticed it isn't vibrating! When I move then ringer button, nothing vibrates. Also, texts, emails, and phone do not cause it to vibrate. Both vibrate settings are set to On in the menu. Anyone else have that problem?
This SAME thing happenend on my first gen iPhone when I got it last August. I thought it was normal. Said nothing of it for a week. Then, I called up Apple, asked them about it, they replaced it for me effortlessly. You have a faulty unit. Get it replaced.