Particles in particle system not being lit

I have a sprite that I want to use in my particle systems (it's just 4x4 white square). I'd also like for the particles to be lit (react to lighting within a scene).

Since I'm using 2D Toolkit, I simply created a new tk2d sprite collection of just the single texture, generating normals for it within the sprite collection settings, set the shader for the atlas0 material that's generated to LitBlendVertex and attached the atlas0 material to the particle system.

However, the particles are not reacting to light. I've tried different shaders (both Unity and tk2d) but to no avail. I also messed with the particle systems normal direction setting but still nothing.

Is there something I'm missing to get particles in a particle system to be lit?