Easy fix Arduino is NOT compatible with the JAVA SE 6.0 , go back to 5.0
Go to the Utilities Folder (cmd+U)
open the Java Folder
open the application Java Preferences
push the button Restore Default ( or similar I have the italian version ) in the Java application pane
OR
move J2SE 5.0 32 bit on top
You're right! Switching to 5.0 cleared up the problem. Thanks so much for your help and quick response (and to the other poster, too: that was an interesting read). Now I can start to play (um, I mean, learn