New problem--my boules come out of the fridge and banneton fine, but seem to spread out instead of going up in the dutch oven.

What does the cross section of the loaf look like? I had a problem like this. In the oven the loaf would spread out and not rise very well. Cross section of the loaf was dense crumb structure along the bottom with large airy pockets along the top of the loaf. 

Problem was underproofing. I was putting the loaves in the fridge before they had risen enough. I started letting my loaves expand a lot bigger before putting them in the fridge and that solved the problem. 

I should note I stopped using the finger push test for testing for a proofed loaf. I am just going by expansion in the second rise--the rise after shaping and putting in the banneton. 

Photos of the loaf and crumb would help.  As well details about your formula, temperature of bulk and how you handled the dough would help.

Dough that doesn’t rise well and spreads out while baking is often secondary to overfermentation/overproofing.  Also, dough with insufficient structure and tension will also spread.

I  just read this yesterday and am anxious to try it.  

http://www.thefreshloaf.com/node/61181/tip-have-faith-oven-spring

I just baked a new loaf. Came out kind of flattish, not a whole lot of spring. Cut into it, even crumb density, no fool's crum at the top of the loaf. I noticed when I was bulk fermenting that the gluten strength was not what I had hoped at each fold. I proceeded to shaping and while shaping a batard I ended up wiht a baguette! I cold retarded it and cooked it straight out of fridge.

There was a large crack running the length of the loaf beneath the ear. 

I think all this suggests I didn't have quite enough gluten strength, either due to not developing it early enough in the ferment or overfermenting and maybe losing gluten integrity and so on.