Trouble with Arduino Robot

Hi I'm having trouble with the Arduino robot.

One example: using af sound sensor module Works simply and perfectly on the Uno board.

Using the same sensor and piece of code on the robot doesn't Work.

The sensor lights up itself (with a Little red led) when sounds is recognised, and can as such be testes even without code.

Again - it Works on the Uno board, but not on the robot control board, both being powered by usb.

Does anyone have any idea of what can be going on ?

A remark: so far the robot has been a disappointment, because it is so very trobulesome to get sensors working in contrast to the Uno board.

regards, Lars, Denmark