Items under the Action Menu in the Get Info window are grayed-out
I need to change the ownership of a file using the permissions section of the 'Get Info' window. After unlocking the permissions by clicking on the padlock and entering my password, the items under the action menu are unavailable - they are grayed out. I think this may be the case with all files, as the random files I've chosen are all showing the action menu with items grayed-out.
I have run the 'Repair permissions' program under Disk Utilities, but that didn't seem to make any difference.
Why are the items under the permissions action menu grayed-out? Any advice would be greatly appreciated.
MacBook Pro Late 2008, Mac OS X (10.5.5)