Same here (albeit in the US) - I'm a Skype newbie. I thought only skype-to-skype calls were free on the iPhone. I've not put any $$$ into my account, but I made a call to a landline phone. According the Skype website this cost me $0.06 - will this end up on my AT&T bill?
I just tried to call my home landline via Skype on my iPhone. I got a popup telling me I didn't have enough Skype credit in my account.