looking at your 2010 pic, I would say that is a lot of stalk for sweet corn, at least what I see around here.

I see you are from Montana.  thinking about what I see in field corn,  I think when you take a short-season hybrid and move it south, it tends to be shorter.  So, one thing that crosses my mind is to try planting a shorter season hybrid.  See if that will give you a shorter stalk, with less lodging potential.

The other thought that crosses my mind is that you are running short of fertilizer. first, if you have not done so, do a soil test and make sure you have adequate phosphorus and potassium.  These are important to get good stalks (especially potassium).  second, consider sidedressing additional nitrogen around the time the corn is ready to tassel.  This might help feed the crop without adding to the stalk height.  This may, or may not, work.  You might be too late with the late nitrogen application.  still, it might be worth trying this year.

Color in the 2012 pic looks a bit yellowish (pale green).  Color in 2010 looks better.  How does the color of the corn leaves look to you throughout the growing season?  decent?  or a bit pale?

I wonder if the real key is to look for a different variety that is more suited to your location.