Masking off the upper nibble of wValue causes the USBDevice library to report it's 6 strings repeatedly, starting on every requested index that is a multiple of 16. This is made evident by using SimpleHIDWrite with the Generic HID example program.

![usb_string_bug](https://f.cloud.github.com/assets/2797902/1986833/2b3290b6-8451-11e3-8dce-86544edb6248.jpg)