Comment 5 for bug 714356

Weird... when I ran "sudo update-manager", the power manager did start -- and it used a brightness settings from somewhere unexpected, like maybe root's profile, because the backlight came on MUCH brighter than when I do a plain "update-manager".

In both cases, the power manager started right as I pressed [install updates].

Out of curiosity, I ran "strace update-manager", and buried in the flood of output was this:
sendmsg(3, {msg_name(0)=NULL, msg_iov(2)=[{"l\1\0\1 \0\0\0\6\0\0\0\210\0\0\0\1\1o\0\25\0\0\0/org/fre"..., 152}, {"\26\0\0\0org.gnome.PowerManager\0\0\0\0\0\0", 32}], msg_controllen=0, msg_flags=0}, MSG_NOSIGNAL) = 184

Alan