I've become confused over my options as the detail is getting more complicated than I can handle. Instead I have searched the mac for all evidence of LW and removed repeating the process a few times. I have now reinstalled and LW did not recognise any previous prefs. LW is now hashing all the tracks again so I shall leave it running in the background for today, leave for a few extra hours to make sure all is OK and then reboot. Hopefully this will fix my repeat hashing problems. I'll keep you updated.