Al, Download and reinstall the Mac OS X 10.5.8 COMBO updater. Worked for me. Cheers, John On Jan 11, 2013, at 6:02 PM, Al Grappone wrote: When trying to open DU I get alert that it quit unexpectedly. Al Grappone (90) USN Ret 20" iMac OS X 10.5.8 2. 1 GHz ,PPCG5. 1GB DDFR2 SDram memory, Mail 3.6, iTunes9.2 iLife9 Quicken2007 16.0.0, Epson Perfection 2450 Photo Scanner, Canon iP5200 Photo Printer,Netgear Wireless-N router