Louis, I will check up on this, but I did not know that Kilz or any primer seals out odors. I actually do not know how this can occur.
What I would do would be to strip out the carpet, pads, and tack strips. Air out the room really well. Throw down alot of baking soda all over the place. Leave it down. Maybe use 10 boxes. After a couple of days, wet vac the stuff up and conduct some smell tests yourself. If its still there, then just rip up the subfloor and start over. Louis, you do not want the new carpet down and later find out that the smell is permeniating through the carpet.