The utempter install scripts use "chown user.group" syntax, which doesn't work in coreutils-5.2.0-4. They need to use a colon instead.
I built a new utempter-0.5.4-1 yesterday that fixes this problem, however it might not have gotten sync'd to the outside world yet. ;o) Thanks for reporting though. P.S. mkxauth has a similar problem, also fixed in 4.3.0-60 which is also not out yet. I hope to have that out soon though.