It should work with the java update though.However try this:
1. Delete everything according to OSBot (Folders -> located in your c drive somewhere, client, etc.)
2. Re-download everything at the home page (scroll down bottom right corner)
3. Try to open it and sign in again.
i've just done this but it doesn't seem to be working /: i get the same problem
I have had members occuring the same problem with mac, someone upgraded to the lion version and it seemed to work, someone else downloaded the right java from the link I have sent you and it worked. So I'd suggest to re download and install the java again, I don't know anything about mac but you might try this JDK version for mac, download and install. Tell me how it goes
i need os x 10.7.3 to download that version of jdk