I am using Lexiloader v21 on Mac OSX version 10.6.8.  I exported some data to a file, modified one of the fields and then tried to update.  However, none of the buttons except Export will do anything.  If I restart Lexiloader and re-login, I can then do an update.  I've recreated this problem multiple times and it is consistent for me.  Anyone have ideas on how to correct?  Thanks!