Thank you for opening this bug and helping make (Myth)Ubuntu better. This is not a bug on 'who'; the only thing 'who' does is read /var/run/utmp, and report based on it. What happens is running programs must use the utmp protocol to update utmp -- so there is at least one such program on 11.10 that is *not* doing that (and this program was the one that populated utmp so that 'checklogin.sh' was working correctly.
Thank you for opening this bug and helping make (Myth)Ubuntu better. This is not a bug on 'who'; the only thing 'who' does is read /var/run/utmp, and report based on it. What happens is running programs must use the utmp protocol to update utmp -- so there is at least one such program on 11.10 that is *not* doing that (and this program was the one that populated utmp so that 'checklogin.sh' was working correctly.
As such, I have reset the package to 'mythtv'.