You receive an error message: USB Controller Bandwidth Exceeded.
USB host ports are limited to a total maximum bandwidth high-speed USB 1.1 devices are capable of moving data at a maximum rate of 12MBps, while low-speed hosts provide 1.5MBps data rates. USB 2.0 devices can theoretically move data at 480 MBps. When a streaming device begins to stream, it reserves bandwidth on the port the device is connected to, limiting the remaining bandwidth available for other devices. A new device may demand additional bandwidth that the port cannot provide. By using a separate USB host port for streaming devices and another host port for additional devices, you can avoid the bandwidth limitations. Note that USB hubs do not constitute host ports but are merely expansions of a main USB host. Bandwidth reservation and limiting bandwidth available to other devices is considered "by design" according to USB specifications and does not indicate a problem with your hardware.
The true Univeral Serial Bus (USB) specification and FAQs about USB are available at http://www.usb.org. You will find additional information at http://www.intel.com/technology/usb/ and http://computer.howstuffworks.com/usb.htm.