libnl, bug question, and lib query

I'll start this up with three different question, hope that's not a
problem instead of sending three different mails.

First I wonder if I should, in a production environment using the
nl80211, stick to use libnl 1.* or should I use use the git 2.0?

Second I have noticed a problem regarding reg set/get which I can't
pin down where it goes wrong (reboot resolves the issue). Following is
how I can reproduce it. Notice all the nonsense input I used. I don't
know what exactly triggers it, but the "set DU seems to be a good
candidate"
wlan:/home/test# iw reg set US
wlan:/home/test# iw reg get
country US:
	(2402 - 2472 @ 40), (3, 27)
	(5170 - 5250 @ 40), (3, 17)
	(5250 - 5330 @ 40), (3, 20), DFS
	(5490 - 5600 @ 40), (3, 20), DFS
	(5650 - 5710 @ 40), (3, 20), DFS
	(5735 - 5835 @ 40), (3, 30)
wlan:/home/test# iw reg set CH
wlan:/home/test# iw reg get
country CH:
	(2402 - 2482 @ 40), (N/A, 20)
	(5170 - 5250 @ 40), (N/A, 20)
	(5250 - 5330 @ 40), (N/A, 20), DFS
	(5490 - 5710 @ 40), (N/A, 27), DFS
wlan:/home/test#  iw reg set DU
wlan:/home/test# iw reg get
country CH: