I have a iPhone 4, but have never had anyone else who had another iPhone 4 that I wanted to call with Facetime.

Now my Mum has an iPod Touch 4th gen, I spent two hours on Skype yesterday talking her through setting iTunes and the iPod up (quite a feat given that my Mum first used Windows six months ago).

I thought it would be fun to have a quick Facetime call with her. So I had her open the Facetime app, sign in and add me as a contact (with my email address that I use for iTunes and my iPhone 4's mobile number).

When she tried to call me it failed, saying something along the lines that she needed to upgrade to iOS 4.1 which is odd (I suspect the message might have been that the person she was trying to call needed to upgrade).

I'd try to call her, but I can't see how I can. My contact entry for her has her email that she uses for iTunes, but crucially there is no Facetime button on the contact record.

Is there some step that we missed on the iPod end to make this work ? I have no way of knowing because I've never seen the Facetime app on the iPod and the iPhone doesn't have the same app.