Modern automatics on smaller cars do tend to do this so it isn't out of the ordinary. You don't say how old the Ibiza is, so we're not sure what type of automatic gearbox it has, as there were various types available, but all of them work like this. There's no 'creep' function as you get on older automatics or larger vehicles - instead you have to touch the throttle to get it to hold immediately. It's strange but seems to be a common feature on this size of car/engine.