Interface Builder ( IB ) font bug?

I noticed in ib, if i choose arial and then bold face (for labels, titles etc) it displays the text properly and is the proper bold. but when i deploy the app the text is gone, what i find wierd is in ib if you choose fonts that are not on iphone the text itself looks like it is the default font (eg. it doesnt let you use none iphone fonts)
so is this a bug with arial bold only?
i also tried to choose regular arial and then on the interface builder top menu i choose font >> bold and it turns the text bold, and it still doesnt display when compiled..

It makes no sense to me to have ib to do interface stuff when something like simple font choosing is buggy and/or not properly supported.