Thank you for answering:
I selected Lilypad Arduino USB
Learned a lot this session trying to get it to work.
Your board Cactus Micro Rev2 is using ATMega32u4 with embedded USB/serial onboard on the chip
I’ve understood it does not need drivers.
But still I cannot get it to work.
The only connection "succes’ I had is by putting it into my extra USB connector on the keyboard. (but I got a warning it had not enough power)
In System Prefferences (Network) I can see a LilypadUSB annoucement as a modem
But that does not show up in the Arduino IDE
The only thing that’s left to try is connecting it though a powered USB hub (maybe more power)
By the way my Arduino Leonardo is working correct with OSX 10.6 an Arduino 1.0.6
I am on Arduino 1.0.6
Cannot go higher because I am using an old Mac Pro with OSX 10.6 (highest operating sys. for this machine)
Newer Arduino IDE requires JAVA 7 and I cannot go higher than JAVA 6 (then I have to trick my OSX)