Sandee,
I have one recipe that sounds like yours, where you heat the liquid and let it cool before mixing in the flour and yeast, then kneading it with the dough hook. It is scrumptious when it turns out light and while still good is dense/heavy when it doesn't.
What I found is I have to watch the amount of flour I use. Because flours can vary in the amount of dryness and is effected by the humidity, etc...the amount of flour you need for any bread recipe can be different than the recipe calls for.
With my recipe it states that the dough should be "wet" but still knead-able by hand, providing I apply grease to my hands so it doesn't stick.
Do you think decreasing the amount of flour called for might help?