Think twice before buying a Pottery Barn rug...

But more specifically, a hand-tufted wool rug. For 2 years I wondered what exactly was causing the musty burnt-rubber smell in our living room. Guests will ask, "What is burning?" on a regular basis. My Dad was convinced we had an electrical problem of some sort. I'd been on my hands and knees several times trying to pinpoint the source of the smell, but now it is official.
Our Pottery Barn rug stinks. It's beautiful, but it stinks. After moving the rug to our den, the odor has also moved to the den. Apparently there is absolutely no way of ridding the smell (not baking soda, not professional cleaning, nothing), as it comes from a latex backing that is used in the rug.

This website explains it all.