In 2.64 when I set up a cube as a smoke domain with a flow object the domain appears transparent as usual however when rendered (Blender or Cycle) it renders as a solid. I can’t get the Domain not render as solid! So I can’t see smoke in render.
Cycles may not be able to render smoke.
For blender renderer have you correcltly set up the domain volume material and voxel texture.
Add a cube, select it and press spacebar. Search for smoke. Select Quick Smoke. This will correctly set up a smoke simulation with correct materials. Compare these materials with the ones you are using.
Thanks, Quick Smoke works great.