Hi

The Mac OS X 10.0.x Installer din't installed the BSD Subsystem by default. The user had to set the checkbox manually. So if you made an upgrade from 10.0.x to 10.2.x it is very likely that the BSD Subsystem wasn't installed either.

Does the following file exists on you Mac?

Your Mac OS X drive -> Library -> Receipts -> BSD.pkg

If not, insert the 1st Mac OS X disk and double click the following file.

Mac OS X Install Disc 1 -> System -> Installation -> Packages -> BSD.pkg