indeed your problem looks to be due to USB bus underpower issue. It could be either, because you use too many bus powered usb devices at the same time, or either that your USB controller is a bit weak (is it a laptop?). Spark has plenty of Leds on it so it's a bit power hungry...
You have two different solutions available to power it:
1 - use a powered usb hub and plug spark on it.
2 - use an external power adapter 9V, 500mA(minimun), center positive (please refer to your spark manual for more details).
Hope it will help