Rinse the rice until the water runs almost clear, then use about 1.25 cups of water per cup of long grain rice. Bring it to a boil, cover, drop to the lowest heat for 15 minutes and then leave it covered off the heat for 10 more. Do not lift the lid. (more)

Usually it is under-proofing or old yeast. Let the dough rise somewhere warm until it has clearly doubled, and test your yeast in warm water with a pinch of sugar: it should foam in ten minutes. (more)