I have a 100-3 model bread machine. Sometimes my bread comes out okay other times it flops completely. What am I doing wrong? Stopped using it for years and then decided to take it out and "try again." It rises just fine (most times), but as soon as the baking cycle starts it caves in. I know you're supposed to add lukewarm water to make the dry yeast work better. Even that doesn't seem to help. Help please!