The term "all-purpose flour" is applied to two totally different types of flour depending on whether it is purchased in the U.S.
. (forgive me, all those who hail from outside North America, I know nothing about your flour)*
Canadian "all-purpose flour" will produce good results in a breadmaker, whereas American "all-purpose flour" will produce poor results. Americans must use bread flour in their breads, and cake flours in their cakes, because their "all-purpose flours" is not nearly as fine as Canadian flour.
Canada has a lot of wheat, and we create a lot of flour. Our all-purpose flour is exactly the same as our bread flours and our cake flours. We only give them these names as a marketing tactic. American bread flour is actually different from American all-purpose flour, because they don't have nearly as much nice flour to choose from, since Canada has sent them all of our crappy flour. Sorry.
*BlueDragon says: bread flour is called 'strong flour' in the UK, then there's 'flour' which is your all-purpose flour, and you can sometimes buy 'cake flour'.