DUE: USB Keyboard demos doesn't work

I have both an Arduino Due and a Taijiuno Clone for one week now. When I connected the Due to my Win7 machine the first time it was recognized as a Due and as a keyboard dependent on the connector.

Now I played with some sketches including USB KeyboardLockout and KeyboardMessage but the Due isn't beeing recognized as a keyboard anymore. When connected to the PC I find in the control panel->devices tab the devices Arduino Due Programming Port (COM14) and a Arduino Due with a warning triangle. I tried to fix this but a specific(?) driver could not be found. Similar behaviour is for the clone.

Any idea what's going on here?

Are the new sketches successfully uploading? What does the IDE say after you hit Upload?

Yep, uploading works. I simply load the example and shift it to the uC.
When the uC is erased the device is recognised as a GPS Camera. I wonder what's going on here. I'm using IDE with Ver 1.5. All is set by default.

What does the IDE say after you hit Upload?

I repeated the prob with the KeyboardMessage example (I have Version 1.5.1r2 of the arduino IDE).
The IDE gives:

Erase flash
Write 10208 bytes to flash

[Then the verify progress bars appear]

Verify 10208 bytes to flash
Verify successful
Set boot flash true
CPU reset.

As always, the Icon changes from "Arduino GPS-Camera" to "Arduino Due" with the warning triangle. Also it is not possible to install a Windows7 driver since the button "update driver..." in the update driver dialog is disabled.

Can you try 1.5.2?

There was a problem with the Native USB code that was fixed in 1.5.2

Hello Louis,
Thank you for your help.

When Nick asked me about the output messages of the IDE (though I stated in the first post everything is fine) I had the slight suspicion that there is something completely wrong outside my influence.
Now I can do further usb tinkering. Are you, Nick or Louis in the "USB business"?
Have some years of AVR/PIC tinkering now but USB is still black art...

Anyway, thank you, guys.

No I'm not in the USB business. I've read about it, and it's damn complex.