K.K.
Hi Shellie,
I have a one year old boy that is doing the same thing. He will throw his head back, scream, and start crying as I walk him up the stairs to his crib. For me, I think my son is doing it out of frustration. I think he wants to be independent. He wants to continue to play with his toys or with me. I have viewed this as him communicating to me that he doesn't want to do what I am telling him he needs to do. Unfortunately, since they can't tell us.. we have to guess. My boy also is extremely happy, smiley, good-natured, and rarely has ever fussed. But, when he turned one things changed a little. He still is SO well behaved with the exception of naptime/bedtime. I have done both ways: let him cry and gone in there to rock him. I have to tell you that I no longer go in there now unless he is hysterical. And mainly I will only go in there to make sure he is not hurt. I found that it only got worse once he saw me because then it reminded him that he wanted to play with me. Plus, I felt like it was such a tease to him. Here comes Mom to get me and then I walk out the door. My advice would be to just it go. Our babies are a lot smarter than we think. They know what works and what doesn't. If you go in there to comfort him, change his diaper, etc. then he ends up getting his way. For a week just try to let him cry it out. It won't hurt him. At first, he may cry for a good 20+ minutes but it will get better. Two other things: I moved up a diaper size which helped as well. And I also increased the food at his meals.
Hope this helps.