What happens when you kill the Samsung Kies Wifi Agent?
It's quite simple to turn this off. I'm using OSX 10.7.4 and I did this:

I went to "System Preferences", then in the line "System" I went to "Users and Groups". At the top, there is "Password" and something like "Login Items". I went to this "Login Items" and just clicked one time in "KiesViaWifiAgent" and then in the " - " button under it.

Now, I can reboot the MacBook Pro and it will not start up by itself.