Drag all three preference files to the desktop with Logic closed.
~/Library/Preferences/com.apple.logic10.plist
~/Library/Preferences/com.apple.logic10.LSSharedFileList
~/Library/Preferences/com.apple.logic.pro.cs
Launch Logic Pro X again.
Strange, I only have the com.apple.logic10.plist file, not the other two.
Anyway, it worked this time, thanks for your persistence
(Oh, and there is some apple pie left Eric!)