Sorting out an old box, I found lot of Gadgeteering boards… Hydra, Cerb, Raptor but also a Panda II and a Spider (EMX).
Now Spider is working fine in MF 4.3, and has last firmware. The problem is that I can’t set the board in USB serial mode for TinyClr bootloader although all micro-switches are set correctly. The board bling-blong windows but it is not recognized in any way (“USB device not recognized”). Settign switches back to normal state (OFF) it works fine as before.
I suspect some hardware failure … but may be I’m missing something due to long time passed …
Any suggestion?
This thread my be of help.
Thank you Greg, I missed the post … 
Anyway I’ve tested 3 different machine and same error.
Good hint to use serial port directly. I will check later.