I can't figure this out. The Valve DOTA2 Texture guide (this is a TF2/general Blender question, bear with me, here) starts out with them saying to bake an AO Map to capture part of the sculptural detail of the normal maps, and the example image they show is apparently an AO Map showing shadowing generated by a normal map (or they have a billion poly bear model that they're baking their normal/ao/light maps out of. Which I guess is possible.)

So I'm trying to create a badge that has some raised text on it (see, TF2), and that'll blow through the poly limit if I try to model the text directly. I can create a normal map for it easily enough in GIMP, but I want some of the detail from the normal map to be reflected in the AO map, because it seems like it should be.

So I apply the normal map and it shows up properly, and then I bake AO, and the AO bakes out flat. I've tried setting the material to effect geometry and ambient, I've tried setting AO to raytrace instead of approximate, no matter what I do, the normal map gets ignored in the AO bake.

Am I missing something? Am I going to have to make a super-high poly version of the badge and bake normals and AO out of it, instead?