since 10.8 was installed on my mac, when i try to update itunes, or airport utility, it always gets stuck on "installing - less than a minute". then i have to shut the computer from the power button since it wont restart or shut down, and then when i try updating again, it gets stuck again. i tried fresh installing, and it happens on the next update. i tried repairing disk and disk permissions, same. why does this happen? am i the only one with this problem? is there a solution?
Anything interesting in console? Have you tried just installing airport and not itunes and vice versa?
Can you try running software update from terminal:
sudo softwareupdate --install --all --verbose