Hardware R4i Save dongle firmware update

[The Exploding Potato]

Just got an R4i save dongle but the firmware uploading software doesn't detect it wich makes it impossible to update the device. I've tried on two different PCs and i can't find anyone else online having the same problem. I follow the instructions give on their site (http://r4i-sdhc.com/UploaderFirmware.asp) but at step 4 nothing happens after i've pressed the button.
Does anyone know what the problem could be?

 

[suparnemo]

Can you try another USB port or computer?

 

[The Exploding Potato]

Can you try another USB port or computer?

I've tried with two PCs and several usb ports on both, but still no reply when I press the button...