In going from Tiger to Leopard, I backed up my HD to an external, but I apparently didn't do it correctly because Migration Assistant acted like the files were not there. So, I manually copied my files over along with select apps & preferences files. I got everything (Firefox, Thunderbird, etc) working exactly how I left them in Tiger. But, I messed up my Address Book and Mail. Now when I try to use them it says "You cannot use this version of the application [app name] with this version of Mac OS X. Is there a way to just reinstall these two apps without starting over with a fresh install?