I also have the problem when adding authors to songs. Also, when importing from a CCLI SongSelect file it adds the author with a space in front of the name, even if the autor is already in the database. Mac OS X 10.6.8.
I've been using the Mas OS X version and it works pretty good. You may get some error messages and I've had an issue with the font size getting small a couple of times, just restarted the program and the font size is back to normal.