I am using Mac OS X 10.8.2. I don't know exactly when it started (might have been after the upgrade to 10.8.2, but not sure), but now, any zip file I try to open starts up 'Archive Utility', but then it just hangs and I have to force quit it. The zip file is never unzipped.

As a workaround, I can go to the command line and use the 'unzip' command, but that is not very convenient.

Can I re-install this application to see if that would help or is this part of the OS and thus cannot really be re-installed separately?