When I try to open Now Contacts 4.5.1. version I get a message saying" can't open because a preferences file could not be created". I am using OS 10.5.8 and have never had this problem before.
1) Make sure you know where your primary contact file is stored on your hard drive. You'll need to know where it is to set it as your primary file again at the end of this process.
2) Quit Now Contact (if it is running).
3) Open a new Finder window and select Home from the Go menu.
4) Once in your Home folder, go to: /Library/Preferences/
5) Find the file named com.poweronsoftware.nowcontact.plist and move it to the desktop.
6) Find the folder named Now Contact Prefs and move it to the desktop as well.
7) Open your Now Contact file and make it your primary contact file (Launch Now Contact, open the File menu, select Open, make sure there is a checkmark next to the option "Make this my primary file," locate your Now Contact file, highlight it and click Open).
Cool Trash the items moved to the desktop in steps 5 and 6.