Currently Being ModeratedNov 16, 2012 7:35 AM (in response to napagokc)
I trashed Garageband preference file (com.apple.garageband.plist). Then I ran Mac system preferences/software updater and rebooted the computer. Then ran Garageband again. It prompted me to download 1.6 GB. I agreed. This time, after the download was complete, I was able to run Garageband with no problems.