I've had my Xoom since March. Barometer HD worked great until I received an update to it. Then it didn't work. It's stuck on 25.34xxxx inHg (inches of Mercury, where xxxx fluctuates).
I thought the update broke it, but the author says nope. His stopped working after a jet flight, but worked OK after he landed.
I went down to the Verizon store and we loaded Barometer HD onto the floor model. Exact same behavior as mine.
Every once in a while (like just now) I install it and check it out, but it still doesn't work.
Dave