I feel your pain!! We got a great deal on a house that smelled like cigarette smoke. We changed the air filters, replaced carpet, removed curtains, and even used 100% chlorox on the walls/wall paper before painting. We used pinesol and Old English on the cabinets and that helped a little bit. I think the wood soaks up just as much as the carpet.
We finally had to bring in a fire-restoration company and they used an industrial strength bacterial spray on the house. It is the same stuff they use when there is actually a FIRE in the house. It worked, but after 3 months of messing with it I would have preferred to spend a little more on the house. They do sell a non-industrial strength version of the bacterial spray at home-depot depending on how bad the smoke smell is. They also recommended we change out the air filters every week until the smell was completely gone.
Good luck I know how frustrating it is!