The mass storage device from Digitech designed for Flash Cards, as found
on (for example) the GNX4 device has issues with residue, similar to the
bug report at http://kerneltrap.org/node/6297. This patch adds the
faulty storage device to unusual_devs.h, this not only reduces the noise
in dmesg but also increases the transfer speeds by a factor of 7x for me
(89kB/s -> 637kB/s).