I would suspect two things. The first is that your dough could stand a little more water, wetter is better THe second is that you could probably knead the dough a little more thoroughly. You can use the window pane test. Take a golf ball sized piece of the dough and pull it in all directions. You should be able to get the dough so thin that you can see through it, with out the dough tearing. If the dough tears, it kneads more kneading.