On Recent image 04302013 for pcDuino3, there are many new features being added, and the peak power consumption increases significantly. Users have reported that the system hang when Arduino IDE launches when there is a shield of large current is installed.  This is due to a USB power cable that is marginal. To improve the stability, we can install an electrolytic capacitor in the range of 200uf to between 5V and GND of the headers. The picture is as following: