Please help. I open System Prefs and click 'Print & Fax'. I click + to add a printer. The dialog box opens for a few seconds and then closes. Just that window. I cannot add a printer at all or even print anything for that matter. I ran Printer Therapy and it finds nothing wrong. Same with TechTool Pro. Nothing seems to be wrong except this. Someone please help. This is a disaster. I even Logged out and tried a different user and it does the same thing! I am running the latest software for everything.