OSX Lion 10.7.3 and Airport Utility 6 Installation Errors

I tried to run a Software Update and install the latest upgrades but the installation fails for both Airport Utility 6 and OSX Lion 10.7.3 updates. Each time, the update is downloaded succesfully then after the installer runs for a while an error pops up on the screen saying something like "Error: A number of files could not be installed" and all you can do is "ok" it. Nothing gets installed. When downloading JUST Airport Utility 6 from the Apple website to attempt a manual install, I get the following error:

I've tried running Fix Disk Permissions on the drive, and even Rpair Disk, but found no errors of any kind on the disk. My disk has over 300GB of available space. The Mac is a 2011 MacBook Pro 2.3Ghz with 4G RAM, currently running 10.7.2.

I've never had ewrrors with an Apple Software Update before, so this is very strange...

Apple, can you please help, or let us know if there will be a fix forthcoming?